tests/SkVMTest.cpp

/*
 * Copyright 2019 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/core/SkColorPriv.h"
#include "include/private/SkColorData.h"
#include "src/core/SkCpu.h"
#include "src/core/SkMSAN.h"
#include "src/core/SkVM.h"
#include "tests/Test.h"
#include "tools/Resources.h"
#include "tools/SkVMBuilders.h"

using Fmt = SrcoverBuilder_F32::Fmt;
const char* fmt_name(Fmt fmt) {
    switch (fmt) {
        case Fmt::A8:        return "A8";
        case Fmt::G8:        return "G8";
        case Fmt::RGBA_8888: return "RGBA_8888";
    }
    return "";
}

static void dump(skvm::Builder& builder, SkWStream* o) {
    skvm::Program program = builder.done();
    builder.dump(o);
    o->writeText("\n");
    program.dump(o);
    o->writeText("\n");
}

template <typename Fn>
static void test_jit_and_interpreter(skvm::Program&& program, Fn&& test) {
    if (program.hasJIT()) {
        test((const skvm::Program&) program);
        program.dropJIT();
    }
    test((const skvm::Program&) program);
}


DEF_TEST(SkVM, r) {
    SkDynamicMemoryWStream buf;

    // Write all combinations of SrcoverBuilder_F32
    for (int s = 0; s < 3; s++)
    for (int d = 0; d < 3; d++) {
        auto srcFmt = (Fmt)s,
             dstFmt = (Fmt)d;
        SrcoverBuilder_F32 builder{srcFmt, dstFmt};

        buf.writeText(fmt_name(srcFmt));
        buf.writeText(" over ");
        buf.writeText(fmt_name(dstFmt));
        buf.writeText("\n");
        dump(builder, &buf);
    }

    // Write the I32 Srcovers also.
    {
        SrcoverBuilder_I32_Naive builder;
        buf.writeText("I32 (Naive) 8888 over 8888\n");
        dump(builder, &buf);
    }

    {
        // Demonstrate the value of program reordering.
        skvm::Builder b;
        skvm::Arg sp = b.varying<int>(),
                  dp = b.varying<int>();

        skvm::I32 byte = b.splat(0xff);

        skvm::I32 src = b.load32(sp),
                  sr  = b.extract(src,  0, byte),
                  sg  = b.extract(src,  8, byte),
                  sb  = b.extract(src, 16, byte),
                  sa  = b.extract(src, 24, byte);

        skvm::I32 dst = b.load32(dp),
                  dr  = b.extract(dst,  0, byte),
                  dg  = b.extract(dst,  8, byte),
                  db  = b.extract(dst, 16, byte),
                  da  = b.extract(dst, 24, byte);

        skvm::I32 R = b.add(sr, dr),
                  G = b.add(sg, dg),
                  B = b.add(sb, db),
                  A = b.add(sa, da);

        skvm::I32 rg = b.pack(R, G, 8),
                  ba = b.pack(B, A, 8),
                  rgba = b.pack(rg, ba, 16);

        b.store32(dp, rgba);

        dump(b, &buf);
    }

    // Our checked in dump expectations assume we have FMA support.
    if (skvm::fma_supported()) {
        sk_sp<SkData> actual = buf.detachAsData();
        bool writeActualAsNewExpectation = false;
        {
            sk_sp<SkData> expected = GetResourceAsData("SkVMTest.expected");
            if (!expected) {
                ERRORF(r, "Couldn't load SkVMTest.expected.");
                writeActualAsNewExpectation = true;

            } else if (!expected->equals(actual.get())) {
                ERRORF(r, "SkVMTest expected\n%.*s\nbut got\n%.*s\n",
                       (int)expected->size(), expected->data(),
                         (int)actual->size(),   actual->data());
                writeActualAsNewExpectation = true;
            }
        }
        if (writeActualAsNewExpectation) {
            SkFILEWStream out(GetResourcePath("SkVMTest.expected").c_str());
            if (out.isValid()) {
                out.write(actual->data(), actual->size());
            }
        }
    }

    auto test_8888 = [&](skvm::Program&& program) {
        uint32_t src[9];
        uint32_t dst[SK_ARRAY_COUNT(src)];

        test_jit_and_interpreter(std::move(program), [&](const skvm::Program& program) {
            for (int i = 0; i < (int)SK_ARRAY_COUNT(src); i++) {
                src[i] = 0xbb007733;
                dst[i] = 0xffaaccee;
            }

            SkPMColor expected = SkPMSrcOver(src[0], dst[0]);  // 0xff2dad73

            program.eval((int)SK_ARRAY_COUNT(src), src, dst);

            // dst is probably 0xff2dad72.
            for (auto got : dst) {
                auto want = expected;
                for (int i = 0; i < 4; i++) {
                    uint8_t d = got  & 0xff,
                            w = want & 0xff;
                    if (abs(d-w) >= 2) {
                        SkDebugf("d %02x, w %02x\n", d,w);
                    }
                    REPORTER_ASSERT(r, abs(d-w) < 2);
                    got  >>= 8;
                    want >>= 8;
                }
            }
        });
    };

    test_8888(SrcoverBuilder_F32{Fmt::RGBA_8888, Fmt::RGBA_8888}.done("srcover_f32"));
    test_8888(SrcoverBuilder_I32_Naive{}.done("srcover_i32_naive"));

    test_jit_and_interpreter(SrcoverBuilder_F32{Fmt::RGBA_8888, Fmt::G8}.done(),
                             [&](const skvm::Program& program) {
        uint32_t src[9];
        uint8_t  dst[SK_ARRAY_COUNT(src)];

        for (int i = 0; i < (int)SK_ARRAY_COUNT(src); i++) {
            src[i] = 0xbb007733;
            dst[i] = 0x42;
        }

        SkPMColor over = SkPMSrcOver(SkPackARGB32(0xbb, 0x33, 0x77, 0x00),
                                     0xff424242);

        uint8_t want = SkComputeLuminance(SkGetPackedR32(over),
                                          SkGetPackedG32(over),
                                          SkGetPackedB32(over));
        program.eval((int)SK_ARRAY_COUNT(src), src, dst);

        for (auto got : dst) {
            REPORTER_ASSERT(r, abs(got-want) < 3);
        }
    });

    test_jit_and_interpreter(SrcoverBuilder_F32{Fmt::A8, Fmt::A8}.done(),
                             [&](const skvm::Program& program) {
        uint8_t src[256],
                dst[256];
        for (int i = 0; i < 256; i++) {
            src[i] = 255 - i;
            dst[i] = i;
        }

        program.eval(256, src, dst);

        for (int i = 0; i < 256; i++) {
            uint8_t want = SkGetPackedA32(SkPMSrcOver(SkPackARGB32(src[i], 0,0,0),
                                                      SkPackARGB32(     i, 0,0,0)));
            REPORTER_ASSERT(r, abs(dst[i]-want) < 2);
        }
    });
}

DEF_TEST(SkVM_eliminate_dead_code, r) {
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<int>();
        skvm::I32 l = b.load32(arg);
        skvm::I32 a = b.add(l, l);
        b.add(a, b.splat(7));
    }

    std::vector<skvm::Instruction> program = b.program();
    REPORTER_ASSERT(r, program.size() == 4);

    program = skvm::eliminate_dead_code(program);
    REPORTER_ASSERT(r, program.size() == 0);
}

DEF_TEST(SkVM_Usage, r) {
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<int>(),
                  buf = b.varying<int>();
        skvm::I32 l = b.load32(arg);
        skvm::I32 a = b.add(l, l);
        skvm::I32 s = b.add(a, b.splat(7));
        b.store32(buf, s);
    }

    skvm::Usage usage{b.program()};
    REPORTER_ASSERT(r, b.program()[0].op == skvm::Op::load32);
    REPORTER_ASSERT(r, usage[0].size() == 2);
    REPORTER_ASSERT(r, b.program()[1].op == skvm::Op::add_i32);
    REPORTER_ASSERT(r, usage[1].size() == 1);
    REPORTER_ASSERT(r, b.program()[2].op == skvm::Op::splat);
    REPORTER_ASSERT(r, usage[2].size() == 1);
    REPORTER_ASSERT(r, b.program()[3].op == skvm::Op::add_i32);
    REPORTER_ASSERT(r, usage[3].size() == 1);
}

DEF_TEST(SkVM_Pointless, r) {
    // Let's build a program with no memory arguments.
    // It should all be pegged as dead code, but we should be able to "run" it.
    skvm::Builder b;
    {
        b.add(b.splat(5.0f),
              b.splat(4.0f));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        for (int N = 0; N < 64; N++) {
            program.eval(N);
        }
    });

    for (const skvm::OptimizedInstruction& inst : b.optimize()) {
        REPORTER_ASSERT(r, inst.death == 0 && inst.can_hoist == true);
    }
}

DEF_TEST(SkVM_memset, r) {
    skvm::Builder b;
    b.store32(b.varying<int>(), b.splat(42));

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& p) {
        int buf[18];
        buf[17] = 47;

        p.eval(17, buf);
        for (int i = 0; i < 17; i++) {
            REPORTER_ASSERT(r, buf[i] == 42);
        }
        REPORTER_ASSERT(r, buf[17] == 47);
    });
}

DEF_TEST(SkVM_memcpy, r) {
    skvm::Builder b;
    {
        auto src = b.varying<int>(),
             dst = b.varying<int>();
        b.store32(dst, b.load32(src));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& p) {
        int src[] = {1,2,3,4,5,6,7,8,9},
            dst[] = {0,0,0,0,0,0,0,0,0};

        p.eval(SK_ARRAY_COUNT(src)-1, src, dst);
        for (size_t i = 0; i < SK_ARRAY_COUNT(src)-1; i++) {
            REPORTER_ASSERT(r, dst[i] == src[i]);
        }
        size_t i = SK_ARRAY_COUNT(src)-1;
        REPORTER_ASSERT(r, dst[i] == 0);
    });
}

DEF_TEST(SkVM_LoopCounts, r) {
    // Make sure we cover all the exact N we want.

    // buf[i] += 1
    skvm::Builder b;
    skvm::Arg arg = b.varying<int>();
    b.store32(arg,
              b.add(b.splat(1),
                    b.load32(arg)));

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int buf[64];
        for (int N = 0; N <= (int)SK_ARRAY_COUNT(buf); N++) {
            for (int i = 0; i < (int)SK_ARRAY_COUNT(buf); i++) {
                buf[i] = i;
            }
            program.eval(N, buf);

            for (int i = 0; i < N; i++) {
                REPORTER_ASSERT(r, buf[i] == i+1);
            }
            for (int i = N; i < (int)SK_ARRAY_COUNT(buf); i++) {
                REPORTER_ASSERT(r, buf[i] == i);
            }
        }
    });
}

DEF_TEST(SkVM_gather32, r) {
    skvm::Builder b;
    {
        skvm::Arg uniforms = b.uniform(),
                  buf      = b.varying<int>();
        skvm::I32 x = b.load32(buf);
        b.store32(buf, b.gather32(uniforms,0, b.bit_and(x, b.splat(7))));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        const int img[] = {12,34,56,78, 90,98,76,54};

        int buf[20];
        for (int i = 0; i < 20; i++) {
            buf[i] = i;
        }

        struct Uniforms {
            const int* img;
        } uniforms{img};

        program.eval(20, &uniforms, buf);
        int i = 0;
        REPORTER_ASSERT(r, buf[i] == 12); i++;
        REPORTER_ASSERT(r, buf[i] == 34); i++;
        REPORTER_ASSERT(r, buf[i] == 56); i++;
        REPORTER_ASSERT(r, buf[i] == 78); i++;
        REPORTER_ASSERT(r, buf[i] == 90); i++;
        REPORTER_ASSERT(r, buf[i] == 98); i++;
        REPORTER_ASSERT(r, buf[i] == 76); i++;
        REPORTER_ASSERT(r, buf[i] == 54); i++;

        REPORTER_ASSERT(r, buf[i] == 12); i++;
        REPORTER_ASSERT(r, buf[i] == 34); i++;
        REPORTER_ASSERT(r, buf[i] == 56); i++;
        REPORTER_ASSERT(r, buf[i] == 78); i++;
        REPORTER_ASSERT(r, buf[i] == 90); i++;
        REPORTER_ASSERT(r, buf[i] == 98); i++;
        REPORTER_ASSERT(r, buf[i] == 76); i++;
        REPORTER_ASSERT(r, buf[i] == 54); i++;

        REPORTER_ASSERT(r, buf[i] == 12); i++;
        REPORTER_ASSERT(r, buf[i] == 34); i++;
        REPORTER_ASSERT(r, buf[i] == 56); i++;
        REPORTER_ASSERT(r, buf[i] == 78); i++;
    });
}

DEF_TEST(SkVM_gathers, r) {
    skvm::Builder b;
    {
        skvm::Arg uniforms = b.uniform(),
                  buf32    = b.varying<int>(),
                  buf16    = b.varying<uint16_t>(),
                  buf8     = b.varying<uint8_t>();

        skvm::I32 x = b.load32(buf32);

        b.store32(buf32, b.gather32(uniforms,0, b.bit_and(x, b.splat( 7))));
        b.store16(buf16, b.gather16(uniforms,0, b.bit_and(x, b.splat(15))));
        b.store8 (buf8 , b.gather8 (uniforms,0, b.bit_and(x, b.splat(31))));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        const int img[] = {12,34,56,78, 90,98,76,54};

        constexpr int N = 20;
        int      buf32[N];
        uint16_t buf16[N];
        uint8_t  buf8 [N];

        for (int i = 0; i < 20; i++) {
            buf32[i] = i;
        }

        struct Uniforms {
            const int* img;
        } uniforms{img};

        program.eval(N, &uniforms, buf32, buf16, buf8);
        int i = 0;
        REPORTER_ASSERT(r, buf32[i] == 12 && buf16[i] == 12 && buf8[i] == 12); i++;
        REPORTER_ASSERT(r, buf32[i] == 34 && buf16[i] ==  0 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 56 && buf16[i] == 34 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 78 && buf16[i] ==  0 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 90 && buf16[i] == 56 && buf8[i] == 34); i++;
        REPORTER_ASSERT(r, buf32[i] == 98 && buf16[i] ==  0 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 76 && buf16[i] == 78 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 54 && buf16[i] ==  0 && buf8[i] ==  0); i++;

        REPORTER_ASSERT(r, buf32[i] == 12 && buf16[i] == 90 && buf8[i] == 56); i++;
        REPORTER_ASSERT(r, buf32[i] == 34 && buf16[i] ==  0 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 56 && buf16[i] == 98 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 78 && buf16[i] ==  0 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 90 && buf16[i] == 76 && buf8[i] == 78); i++;
        REPORTER_ASSERT(r, buf32[i] == 98 && buf16[i] ==  0 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 76 && buf16[i] == 54 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 54 && buf16[i] ==  0 && buf8[i] ==  0); i++;

        REPORTER_ASSERT(r, buf32[i] == 12 && buf16[i] == 12 && buf8[i] == 90); i++;
        REPORTER_ASSERT(r, buf32[i] == 34 && buf16[i] ==  0 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 56 && buf16[i] == 34 && buf8[i] ==  0); i++;
        REPORTER_ASSERT(r, buf32[i] == 78 && buf16[i] ==  0 && buf8[i] ==  0); i++;
    });
}

DEF_TEST(SkVM_gathers2, r) {
    skvm::Builder b;
    {
        skvm::Arg uniforms = b.uniform(),
                  buf32    = b.varying<int>(),
                  buf16    = b.varying<uint16_t>(),
                  buf8     = b.varying<uint8_t>();

        skvm::I32 x = b.load32(buf32);

        b.store32(buf32, b.gather32(uniforms,0, x));
        b.store16(buf16, b.gather16(uniforms,0, x));
        b.store8 (buf8 , b.gather8 (uniforms,0, x));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        uint8_t img[256];
        for (int i = 0; i < 256; i++) {
            img[i] = i;
        }

        int      buf32[64];
        uint16_t buf16[64];
        uint8_t  buf8 [64];

        for (int i = 0; i < 64; i++) {
            buf32[i] = (i*47)&63;
            buf16[i] = 0;
            buf8 [i] = 0;
        }

        struct Uniforms {
            const uint8_t* img;
        } uniforms{img};

        program.eval(64, &uniforms, buf32, buf16, buf8);

        for (int i = 0; i < 64; i++) {
            REPORTER_ASSERT(r, buf8[i] == ((i*47)&63));  // 0,47,30,13,60,...
        }

        REPORTER_ASSERT(r, buf16[ 0] == 0x0100);
        REPORTER_ASSERT(r, buf16[63] == 0x2322);

        REPORTER_ASSERT(r, buf32[ 0] == 0x03020100);
        REPORTER_ASSERT(r, buf32[63] == 0x47464544);
    });
}

DEF_TEST(SkVM_bitops, r) {
    skvm::Builder b;
    {
        skvm::Arg ptr = b.varying<int>();

        skvm::I32 x = b.load32(ptr);

        x = b.bit_and  (x, b.splat(0xf1));  // 0x40
        x = b.bit_or   (x, b.splat(0x80));  // 0xc0
        x = b.bit_xor  (x, b.splat(0xfe));  // 0x3e
        x = b.bit_clear(x, b.splat(0x30));  // 0x0e

        x = b.shl(x, 28);  // 0xe000'0000
        x = b.sra(x, 28);  // 0xffff'fffe
        x = b.shr(x,  1);  // 0x7fff'ffff

        b.store32(ptr, x);
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int x = 0x42;
        program.eval(1, &x);
        REPORTER_ASSERT(r, x == 0x7fff'ffff);
    });
}

DEF_TEST(SkVM_select_is_NaN, r) {
    skvm::Builder b;
    {
        skvm::Arg src = b.varying<float>(),
                  dst = b.varying<float>();

        skvm::F32 x = b.loadF(src);
        x = select(is_NaN(x), b.splat(0.0f)
                            , x);
        b.storeF(dst, x);
    }

    std::vector<skvm::OptimizedInstruction> program = b.optimize();
    REPORTER_ASSERT(r, program.size() == 4);
    REPORTER_ASSERT(r, program[0].op == skvm::Op::load32);
    REPORTER_ASSERT(r, program[1].op == skvm::Op::neq_f32);
    REPORTER_ASSERT(r, program[2].op == skvm::Op::bit_clear);
    REPORTER_ASSERT(r, program[3].op == skvm::Op::store32);

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        // ±NaN, ±0, ±1, ±inf
        uint32_t src[] = {0x7f80'0001, 0xff80'0001, 0x0000'0000, 0x8000'0000,
                          0x3f80'0000, 0xbf80'0000, 0x7f80'0000, 0xff80'0000};
        uint32_t dst[SK_ARRAY_COUNT(src)];
        program.eval(SK_ARRAY_COUNT(src), src, dst);

        for (int i = 0; i < (int)SK_ARRAY_COUNT(src); i++) {
            REPORTER_ASSERT(r, dst[i] == (i < 2 ? 0 : src[i]));
        }
    });
}

DEF_TEST(SkVM_f32, r) {
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<float>();

        skvm::F32 x = b.loadF(arg),
                  y = b.add(x,x),   // y = 2x
                  z = b.sub(y,x),   // z = 2x-x = x
                  w = b.div(z,x);   // w = x/x = 1
        b.storeF(arg, w);
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        float buf[] = { 1,2,3,4,5,6,7,8,9 };
        program.eval(SK_ARRAY_COUNT(buf), buf);
        for (float v : buf) {
            REPORTER_ASSERT(r, v == 1.0f);
        }
    });
}

DEF_TEST(SkVM_cmp_i32, r) {
    skvm::Builder b;
    {
        skvm::I32 x = b.load32(b.varying<int>());

        auto to_bit = [&](int shift, skvm::I32 mask) {
            return b.shl(b.bit_and(mask, b.splat(0x1)), shift);
        };

        skvm::I32 m = b.splat(0);
        m = b.bit_or(m, to_bit(0, b. eq(x, b.splat(0))));
        m = b.bit_or(m, to_bit(1, b.neq(x, b.splat(1))));
        m = b.bit_or(m, to_bit(2, b. lt(x, b.splat(2))));
        m = b.bit_or(m, to_bit(3, b.lte(x, b.splat(3))));
        m = b.bit_or(m, to_bit(4, b. gt(x, b.splat(4))));
        m = b.bit_or(m, to_bit(5, b.gte(x, b.splat(5))));

        b.store32(b.varying<int>(), m);
    }
    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int in[] = { 0,1,2,3,4,5,6,7,8,9 };
        int out[SK_ARRAY_COUNT(in)];

        program.eval(SK_ARRAY_COUNT(in), in, out);

        REPORTER_ASSERT(r, out[0] == 0b001111);
        REPORTER_ASSERT(r, out[1] == 0b001100);
        REPORTER_ASSERT(r, out[2] == 0b001010);
        REPORTER_ASSERT(r, out[3] == 0b001010);
        REPORTER_ASSERT(r, out[4] == 0b000010);
        for (int i = 5; i < (int)SK_ARRAY_COUNT(out); i++) {
            REPORTER_ASSERT(r, out[i] == 0b110010);
        }
    });
}

DEF_TEST(SkVM_cmp_f32, r) {
    skvm::Builder b;
    {
        skvm::F32 x = b.loadF(b.varying<float>());

        auto to_bit = [&](int shift, skvm::I32 mask) {
            return b.shl(b.bit_and(mask, b.splat(0x1)), shift);
        };

        skvm::I32 m = b.splat(0);
        m = b.bit_or(m, to_bit(0, b. eq(x, b.splat(0.0f))));
        m = b.bit_or(m, to_bit(1, b.neq(x, b.splat(1.0f))));
        m = b.bit_or(m, to_bit(2, b. lt(x, b.splat(2.0f))));
        m = b.bit_or(m, to_bit(3, b.lte(x, b.splat(3.0f))));
        m = b.bit_or(m, to_bit(4, b. gt(x, b.splat(4.0f))));
        m = b.bit_or(m, to_bit(5, b.gte(x, b.splat(5.0f))));

        b.store32(b.varying<int>(), m);
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        float in[] = { 0,1,2,3,4,5,6,7,8,9 };
        int out[SK_ARRAY_COUNT(in)];

        program.eval(SK_ARRAY_COUNT(in), in, out);

        REPORTER_ASSERT(r, out[0] == 0b001111);
        REPORTER_ASSERT(r, out[1] == 0b001100);
        REPORTER_ASSERT(r, out[2] == 0b001010);
        REPORTER_ASSERT(r, out[3] == 0b001010);
        REPORTER_ASSERT(r, out[4] == 0b000010);
        for (int i = 5; i < (int)SK_ARRAY_COUNT(out); i++) {
            REPORTER_ASSERT(r, out[i] == 0b110010);
        }
    });
}

DEF_TEST(SkVM_index, r) {
    skvm::Builder b;
    b.store32(b.varying<int>(), b.index());

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int buf[23];
        program.eval(SK_ARRAY_COUNT(buf), buf);
        for (int i = 0; i < (int)SK_ARRAY_COUNT(buf); i++) {
            REPORTER_ASSERT(r, buf[i] == (int)SK_ARRAY_COUNT(buf)-i);
        }
    });
}

DEF_TEST(SkVM_mad, r) {
    // This program is designed to exercise the tricky corners of instruction
    // and register selection for Op::mad_f32.

    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<int>();

        skvm::F32 x = b.to_f32(b.load32(arg)),
                  y = b.mad(x,x,x),   // x is needed in the future, so r[x] != r[y].
                  z = b.mad(y,y,x),   // y is needed in the future, but r[z] = r[x] is ok.
                  w = b.mad(z,z,y),   // w can alias z but not y.
                  v = b.mad(w,y,w);   // Got to stop somewhere.
        b.store32(arg, b.trunc(v));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int x = 2;
        program.eval(1, &x);
        // x = 2
        // y = 2*2 + 2 = 6
        // z = 6*6 + 2 = 38
        // w = 38*38 + 6 = 1450
        // v = 1450*6 + 1450 = 10150
        REPORTER_ASSERT(r, x == 10150);
    });
}

DEF_TEST(SkVM_fms, r) {
    // Create a pattern that can be peepholed into an Op::fms_f32.
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<int>();

        skvm::F32 x = b.to_f32(b.load32(arg)),
                  v = b.sub(b.mul(x, b.splat(2.0f)),
                            b.splat(1.0f));
        b.store32(arg, b.trunc(v));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int buf[] = {0,1,2,3,4,5,6,7,8,9,10};
        program.eval((int)SK_ARRAY_COUNT(buf), &buf);

        for (int i = 0; i < (int)SK_ARRAY_COUNT(buf); i++) {
            REPORTER_ASSERT(r, buf[i] = 2*i-1);
        }
    });
}

DEF_TEST(SkVM_fnma, r) {
    // Create a pattern that can be peepholed into an Op::fnma_f32.
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<int>();

        skvm::F32 x = b.to_f32(b.load32(arg)),
                  v = b.sub(b.splat(1.0f),
                            b.mul(x, b.splat(2.0f)));
        b.store32(arg, b.trunc(v));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int buf[] = {0,1,2,3,4,5,6,7,8,9,10};
        program.eval((int)SK_ARRAY_COUNT(buf), &buf);

        for (int i = 0; i < (int)SK_ARRAY_COUNT(buf); i++) {
            REPORTER_ASSERT(r, buf[i] = 1-2*i);
        }
    });
}

DEF_TEST(SkVM_madder, r) {
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<float>();

        skvm::F32 x = b.loadF(arg),
                  y = b.mad(x,x,x),   // x is needed in the future, so r[x] != r[y].
                  z = b.mad(y,x,y),   // r[x] can be reused after this instruction, but not r[y].
                  w = b.mad(y,y,z);
        b.storeF(arg, w);
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        float x = 2.0f;
        // y = 2*2 + 2 = 6
        // z = 6*2 + 6 = 18
        // w = 6*6 + 18 = 54
        program.eval(1, &x);
        REPORTER_ASSERT(r, x == 54.0f);
    });
}

DEF_TEST(SkVM_floor, r) {
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<float>();
        b.storeF(arg, b.floor(b.loadF(arg)));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        float buf[]  = { -2.0f, -1.5f, -1.0f, 0.0f, 1.0f, 1.5f, 2.0f };
        float want[] = { -2.0f, -2.0f, -1.0f, 0.0f, 1.0f, 1.0f, 2.0f };
        program.eval(SK_ARRAY_COUNT(buf), buf);
        for (int i = 0; i < (int)SK_ARRAY_COUNT(buf); i++) {
            REPORTER_ASSERT(r, buf[i] == want[i]);
        }
    });
}

DEF_TEST(SkVM_round, r) {
    skvm::Builder b;
    {
        skvm::Arg src = b.varying<float>();
        skvm::Arg dst = b.varying<int>();
        b.store32(dst, b.round(b.loadF(src)));
    }

    // The test cases on exact 0.5f boundaries assume the current rounding mode is nearest even.
    // We haven't explicitly guaranteed that here... it just probably is.
    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        float buf[]  = { -1.5f, -0.5f, 0.0f, 0.5f, 0.2f, 0.6f, 1.0f, 1.4f, 1.5f, 2.0f };
        int want[] =   { -2   ,  0   , 0   , 0   , 0   , 1   , 1   , 1   , 2   , 2    };
        int dst[SK_ARRAY_COUNT(buf)];

        program.eval(SK_ARRAY_COUNT(buf), buf, dst);
        for (int i = 0; i < (int)SK_ARRAY_COUNT(dst); i++) {
            REPORTER_ASSERT(r, dst[i] == want[i]);
        }
    });
}

DEF_TEST(SkVM_min, r) {
    skvm::Builder b;
    {
        skvm::Arg src1 = b.varying<float>();
        skvm::Arg src2 = b.varying<float>();
        skvm::Arg dst = b.varying<float>();

        b.storeF(dst, b.min(b.loadF(src1), b.loadF(src2)));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        float s1[]  =  { 0.0f, 1.0f, 4.0f, -1.0f, -1.0f};
        float s2[]  =  { 0.0f, 2.0f, 3.0f,  1.0f, -2.0f};
        float want[] = { 0.0f, 1.0f, 3.0f, -1.0f, -2.0f};
        float d[SK_ARRAY_COUNT(s1)];
        program.eval(SK_ARRAY_COUNT(d), s1, s2, d);
        for (int i = 0; i < (int)SK_ARRAY_COUNT(d); i++) {
          REPORTER_ASSERT(r, d[i] == want[i]);
        }
    });
}

DEF_TEST(SkVM_max, r) {
    skvm::Builder b;
    {
        skvm::Arg src1 = b.varying<float>();
        skvm::Arg src2 = b.varying<float>();
        skvm::Arg dst = b.varying<float>();

        b.storeF(dst, b.max(b.loadF(src1), b.loadF(src2)));
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        float s1[]  =  { 0.0f, 1.0f, 4.0f, -1.0f, -1.0f};
        float s2[]  =  { 0.0f, 2.0f, 3.0f,  1.0f, -2.0f};
        float want[] = { 0.0f, 2.0f, 4.0f,  1.0f, -1.0f};
        float d[SK_ARRAY_COUNT(s1)];
        program.eval(SK_ARRAY_COUNT(d), s1, s2, d);
        for (int i = 0; i < (int)SK_ARRAY_COUNT(d); i++) {
          REPORTER_ASSERT(r, d[i] == want[i]);
        }
    });
}

DEF_TEST(SkVM_hoist, r) {
    // This program uses enough constants that it will fail to JIT if we hoist them.
    // The JIT will try again without hoisting, and that'll just need 2 registers.
    skvm::Builder b;
    {
        skvm::Arg arg = b.varying<int>();
        skvm::I32 x = b.load32(arg);
        for (int i = 0; i < 32; i++) {
            x = b.add(x, b.splat(i));
        }
        b.store32(arg, x);
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int x = 4;
        program.eval(1, &x);
        // x += 0 + 1 + 2 + 3 + ... + 30 + 31
        // x += 496
        REPORTER_ASSERT(r, x == 500);
    });
}

DEF_TEST(SkVM_select, r) {
    skvm::Builder b;
    {
        skvm::Arg buf = b.varying<int>();

        skvm::I32 x = b.load32(buf);

        x = b.select( b.gt(x, b.splat(4)), x, b.splat(42) );

        b.store32(buf, x);
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int buf[] = { 0,1,2,3,4,5,6,7,8 };
        program.eval(SK_ARRAY_COUNT(buf), buf);
        for (int i = 0; i < (int)SK_ARRAY_COUNT(buf); i++) {
            REPORTER_ASSERT(r, buf[i] == (i > 4 ? i : 42));
        }
    });
}

DEF_TEST(SkVM_NewOps, r) {
    // Exercise a somewhat arbitrary set of new ops.
    skvm::Builder b;
    {
        skvm::Arg buf      = b.varying<int16_t>(),
                  uniforms = b.uniform();

        skvm::I32 x = b.load16(buf);

        const size_t kPtr = sizeof(const int*);

        x = b.add(x, b.uniform32(uniforms, kPtr+0));
        x = b.mul(x, b.uniform8 (uniforms, kPtr+4));
        x = b.sub(x, b.uniform16(uniforms, kPtr+6));

        skvm::I32 limit = b.uniform32(uniforms, kPtr+8);
        x = b.select(b.lt(x, b.splat(0)), b.splat(0), x);
        x = b.select(b.gt(x, limit     ), limit     , x);

        x = b.gather8(uniforms,0, x);

        b.store16(buf, x);
    }

    if ((false)) {
        SkDynamicMemoryWStream buf;
        dump(b, &buf);
        sk_sp<SkData> blob = buf.detachAsData();
        SkDebugf("%.*s\n", blob->size(), blob->data());
    }

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        const int N = 31;
        int16_t buf[N];
        for (int i = 0; i < N; i++) {
            buf[i] = i;
        }

        const int M = 16;
        uint8_t img[M];
        for (int i = 0; i < M; i++) {
            img[i] = i*i;
        }

        struct {
            const uint8_t* img;
            int      add   = 5;
            uint8_t  mul   = 3;
            uint16_t sub   = 18;
            int      limit = M-1;
        } uniforms{img};

        program.eval(N, buf, &uniforms);

        for (int i = 0; i < N; i++) {
            // Our first math calculates x = (i+5)*3 - 18 a.k.a 3*(i-1).
            int x = 3*(i-1);

            // Then that's pinned to the limits of img.
            if (i < 2) { x =  0; }  // Notice i == 1 hits x == 0 exactly...
            if (i > 5) { x = 15; }  // ...and i == 6 hits x == 15 exactly
            REPORTER_ASSERT(r, buf[i] == img[x]);
        }
    });
}

DEF_TEST(SkVM_sqrt, r) {
    skvm::Builder b;
    auto buf = b.varying<int>();
    b.storeF(buf, b.sqrt(b.loadF(buf)));

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        constexpr int K = 17;
        float buf[K];
        for (int i = 0; i < K; i++) {
            buf[i] = (float)(i*i);
        }

        // x^2 -> x
        program.eval(K, buf);

        for (int i = 0; i < K; i++) {
            REPORTER_ASSERT(r, buf[i] == (float)i);
        }
    });
}

DEF_TEST(SkVM_MSAN, r) {
    // This little memset32() program should be able to JIT, but if we run that
    // JIT code in an MSAN build, it won't see the writes initialize buf.  So
    // this tests that we're using the interpreter instead.
    skvm::Builder b;
    b.store32(b.varying<int>(), b.splat(42));

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        constexpr int K = 17;
        int buf[K];                 // Intentionally uninitialized.
        program.eval(K, buf);
        sk_msan_assert_initialized(buf, buf+K);
        for (int x : buf) {
            REPORTER_ASSERT(r, x == 42);
        }
    });
}

DEF_TEST(SkVM_assert, r) {
    skvm::Builder b;
    b.assert_true(b.lt(b.load32(b.varying<int>()),
                       b.splat(42)));

    test_jit_and_interpreter(b.done(), [&](const skvm::Program& program) {
        int buf[] = { 0,1,2,3,4,5,6,7,8,9 };
        program.eval(SK_ARRAY_COUNT(buf), buf);
    });
}

DEF_TEST(SkVM_premul, reporter) {
    // Test that premul is short-circuited when alpha is known opaque.
    {
        skvm::Builder p;
        auto rptr = p.varying<int>(),
             aptr = p.varying<int>();

        skvm::F32 r = p.loadF(rptr),
                  g = p.splat(0.0f),
                  b = p.splat(0.0f),
                  a = p.loadF(aptr);

        p.premul(&r, &g, &b, a);
        p.storeF(rptr, r);

        // load red, load alpha, red *= alpha, store red
        REPORTER_ASSERT(reporter, p.done().instructions().size() == 4);
    }

    {
        skvm::Builder p;
        auto rptr = p.varying<int>();

        skvm::F32 r = p.loadF(rptr),
                  g = p.splat(0.0f),
                  b = p.splat(0.0f),
                  a = p.splat(1.0f);

        p.premul(&r, &g, &b, a);
        p.storeF(rptr, r);

        // load red, store red
        REPORTER_ASSERT(reporter, p.done().instructions().size() == 2);
    }

    // Same deal for unpremul.
    {
        skvm::Builder p;
        auto rptr = p.varying<int>(),
             aptr = p.varying<int>();

        skvm::F32 r = p.loadF(rptr),
                  g = p.splat(0.0f),
                  b = p.splat(0.0f),
                  a = p.loadF(aptr);

        p.unpremul(&r, &g, &b, a);
        p.storeF(rptr, r);

        // load red, load alpha, a bunch of unpremul instructions, store red
        REPORTER_ASSERT(reporter, p.done().instructions().size() >= 4);
    }

    {
        skvm::Builder p;
        auto rptr = p.varying<int>();

        skvm::F32 r = p.loadF(rptr),
                  g = p.splat(0.0f),
                  b = p.splat(0.0f),
                  a = p.splat(1.0f);

        p.unpremul(&r, &g, &b, a);
        p.storeF(rptr, r);

        // load red, store red
        REPORTER_ASSERT(reporter, p.done().instructions().size() == 2);
    }
}

template <typename Fn>
static void test_asm(skiatest::Reporter* r, Fn&& fn, std::initializer_list<uint8_t> expected) {
    uint8_t buf[4096];
    skvm::Assembler a{buf};
    fn(a);

    REPORTER_ASSERT(r, a.size() == expected.size());

    auto got = (const uint8_t*)buf,
         want = expected.begin();
    for (int i = 0; i < (int)std::min(a.size(), expected.size()); i++) {
        REPORTER_ASSERT(r, got[i] == want[i],
                        "byte %d was %02x, want %02x", i, got[i], want[i]);
    }
}

DEF_TEST(SkVM_Assembler, r) {
    // Easiest way to generate test cases is
    //
    //   echo '...some asm...' | llvm-mc -show-encoding -x86-asm-syntax=intel
    //
    // The -x86-asm-syntax=intel bit is optional, controlling the
    // input syntax only; the output will always be AT&T  op x,y,dst style.
    // Our APIs read more like Intel op dst,x,y as op(dst,x,y), so I find
    // that a bit easier to use here, despite maybe favoring AT&T overall.

    using A = skvm::Assembler;
    // Our exit strategy from AVX code.
    test_asm(r, [&](A& a) {
        a.int3();
        a.vzeroupper();
        a.ret();
    },{
        0xcc,
        0xc5, 0xf8, 0x77,
        0xc3,
    });

    // Align should pad with zero
    test_asm(r, [&](A& a) {
        a.ret();
        a.align(4);
    },{
        0xc3,
        0x00, 0x00, 0x00,
    });

    test_asm(r, [&](A& a) {
        a.add(A::rax, 8);       // Always good to test rax.
        a.sub(A::rax, 32);

        a.add(A::rdi, 12);      // Last 0x48 REX
        a.sub(A::rdi, 8);

        a.add(A::r8 , 7);       // First 0x49 REX
        a.sub(A::r8 , 4);

        a.add(A::rsi, 128);     // Requires 4 byte immediate.
        a.sub(A::r8 , 1000000);

        a.add(A::Mem{A::rsi}, 7);                       // addq $7, (%rsi)
        a.add(A::Mem{A::rsi, 12}, 7);                   // addq $7, 12(%rsi)
        a.add(A::Mem{A::rsp, 12}, 7);                   // addq $7, 12(%rsp)
        a.add(A::Mem{A::rsp, 12, A::rax, A::FOUR}, 7);  // addq $7, 12(%rsp,%rax,4)
        a.add(A::Mem{A::r11, 12, A::r8 , A::TWO }, 7);  // addq $7, 12(%r11,%r8,2)
        a.add(A::Mem{A::r11, 12, A::rax}         , 7);  // addq $7, 12(%r11,%rax)
        a.add(A::Mem{A::rax, 12, A::r11}         , 7);  // addq $7, 12(%rax,%r11)

        a.sub(A::Mem{A::rax, 12, A::r11}         , 7);  // subq $7, 12(%rax,%r11)

        a.add(       A::rax     , A::rcx);              // addq %rcx, %rax
        a.add(A::Mem{A::rax}    , A::rcx);              // addq %rcx, (%rax)
        a.add(A::Mem{A::rax, 12}, A::rcx);              // addq %rcx, 12(%rax)
        a.add(A::rcx, A::Mem{A::rax, 12});              // addq 12(%rax), %rcx

        a.sub(A::rcx, A::Mem{A::rax, 12});              // subq 12(%rax), %rcx
    },{
        0x48, 0x83, 0b11'000'000, 0x08,
        0x48, 0x83, 0b11'101'000, 0x20,

        0x48, 0x83, 0b11'000'111, 0x0c,
        0x48, 0x83, 0b11'101'111, 0x08,

        0x49, 0x83, 0b11'000'000, 0x07,
        0x49, 0x83, 0b11'101'000, 0x04,

        0x48, 0x81, 0b11'000'110, 0x80, 0x00, 0x00, 0x00,
        0x49, 0x81, 0b11'101'000, 0x40, 0x42, 0x0f, 0x00,

        0x48,0x83,0x06,0x07,
        0x48,0x83,0x46,0x0c,0x07,
        0x48,0x83,0x44,0x24,0x0c,0x07,
        0x48,0x83,0x44,0x84,0x0c,0x07,
        0x4b,0x83,0x44,0x43,0x0c,0x07,
        0x49,0x83,0x44,0x03,0x0c,0x07,
        0x4a,0x83,0x44,0x18,0x0c,0x07,

        0x4a,0x83,0x6c,0x18,0x0c,0x07,

        0x48,0x01,0xc8,
        0x48,0x01,0x08,
        0x48,0x01,0x48,0x0c,
        0x48,0x03,0x48,0x0c,
        0x48,0x2b,0x48,0x0c,
    });


    test_asm(r, [&](A& a) {
        a.vpaddd (A::ymm0, A::ymm1, A::ymm2);  // Low registers and 0x0f map     -> 2-byte VEX.
        a.vpaddd (A::ymm8, A::ymm1, A::ymm2);  // A high dst register is ok      -> 2-byte VEX.
        a.vpaddd (A::ymm0, A::ymm8, A::ymm2);  // A high first argument register -> 2-byte VEX.
        a.vpaddd (A::ymm0, A::ymm1, A::ymm8);  // A high second argument         -> 3-byte VEX.
        a.vpmulld(A::ymm0, A::ymm1, A::ymm2);  // Using non-0x0f map instruction -> 3-byte VEX.
        a.vpsubd (A::ymm0, A::ymm1, A::ymm2);  // Test vpsubd to ensure argument order is right.
    },{
        /*    VEX     */ /*op*/ /*modRM*/
        0xc5,       0xf5, 0xfe, 0xc2,
        0xc5,       0x75, 0xfe, 0xc2,
        0xc5,       0xbd, 0xfe, 0xc2,
        0xc4, 0xc1, 0x75, 0xfe, 0xc0,
        0xc4, 0xe2, 0x75, 0x40, 0xc2,
        0xc5,       0xf5, 0xfa, 0xc2,
    });

    test_asm(r, [&](A& a) {
        A::Label l;
        a.vcmpeqps (A::ymm0, A::ymm1, &l);      // vcmpeqps 0x1c(%rip), %ymm1, %ymm0
        a.vpcmpeqd (A::ymm0, A::ymm1, A::ymm2);
        a.vpcmpgtd (A::ymm0, A::ymm1, A::ymm2);
        a.vcmpeqps (A::ymm0, A::ymm1, A::ymm2);
        a.vcmpltps (A::ymm0, A::ymm1, A::ymm2);
        a.vcmpleps (A::ymm0, A::ymm1, A::ymm2);
        a.vcmpneqps(A::ymm0, A::ymm1, A::ymm2);
        a.label(&l);   // 28 bytes after the vcmpeqps that uses it.
    },{
        0xc5,0xf4,0xc2,0x05,0x1c,0x00,0x00,0x00,0x00,
        0xc5,0xf5,0x76,0xc2,
        0xc5,0xf5,0x66,0xc2,
        0xc5,0xf4,0xc2,0xc2,0x00,
        0xc5,0xf4,0xc2,0xc2,0x01,
        0xc5,0xf4,0xc2,0xc2,0x02,
        0xc5,0xf4,0xc2,0xc2,0x04,
    });

    test_asm(r, [&](A& a) {
        a.vminps(A::ymm0, A::ymm1, A::ymm2);
        a.vmaxps(A::ymm0, A::ymm1, A::ymm2);
    },{
        0xc5,0xf4,0x5d,0xc2,
        0xc5,0xf4,0x5f,0xc2,
    });

    test_asm(r, [&](A& a) {
        a.vpblendvb(A::ymm0, A::ymm1, A::ymm2, A::ymm3);
    },{
        0xc4,0xe3,0x75, 0x4c, 0xc2, 0x30,
    });

    test_asm(r, [&](A& a) {
        a.vpsrld(A::ymm15, A::ymm2, 8);
        a.vpsrld(A::ymm0 , A::ymm8, 5);
    },{
        0xc5,     0x85, 0x72,0xd2, 0x08,
        0xc4,0xc1,0x7d, 0x72,0xd0, 0x05,
    });

    test_asm(r, [&](A& a) {
        a.vpermq(A::ymm1, A::ymm2, 5);
    },{
        0xc4,0xe3,0xfd, 0x00,0xca, 0x05,
    });

    test_asm(r, [&](A& a) {
        a.vroundps(A::ymm1, A::ymm2, A::NEAREST);
        a.vroundps(A::ymm1, A::ymm2, A::FLOOR);
        a.vroundps(A::ymm1, A::ymm2, A::CEIL);
        a.vroundps(A::ymm1, A::ymm2, A::TRUNC);
    },{
        0xc4,0xe3,0x7d,0x08,0xca,0x00,
        0xc4,0xe3,0x7d,0x08,0xca,0x01,
        0xc4,0xe3,0x7d,0x08,0xca,0x02,
        0xc4,0xe3,0x7d,0x08,0xca,0x03,
    });

    test_asm(r, [&](A& a) {
        A::Label l;
        a.label(&l);
        a.byte(1);
        a.byte(2);
        a.byte(3);
        a.byte(4);

        a.vbroadcastss(A::ymm0 , &l);
        a.vbroadcastss(A::ymm1 , &l);
        a.vbroadcastss(A::ymm8 , &l);
        a.vbroadcastss(A::ymm15, &l);

        a.vpshufb(A::ymm4, A::ymm3, &l);
        a.vpaddd (A::ymm4, A::ymm3, &l);
        a.vpsubd (A::ymm4, A::ymm3, &l);

        a.vptest(A::ymm4, &l);

        a.vmulps (A::ymm4, A::ymm3, &l);
    },{
        0x01, 0x02, 0x03, 0x4,

        /*     VEX    */  /*op*/ /*   ModRM    */  /*     offset     */
        0xc4, 0xe2, 0x7d,  0x18,   0b00'000'101,   0xf3,0xff,0xff,0xff,   // 0xfffffff3 == -13
        0xc4, 0xe2, 0x7d,  0x18,   0b00'001'101,   0xea,0xff,0xff,0xff,   // 0xffffffea == -22
        0xc4, 0x62, 0x7d,  0x18,   0b00'000'101,   0xe1,0xff,0xff,0xff,   // 0xffffffe1 == -31
        0xc4, 0x62, 0x7d,  0x18,   0b00'111'101,   0xd8,0xff,0xff,0xff,   // 0xffffffd8 == -40

        0xc4, 0xe2, 0x65,  0x00,   0b00'100'101,   0xcf,0xff,0xff,0xff,   // 0xffffffcf == -49

        0xc5, 0xe5,        0xfe,   0b00'100'101,   0xc7,0xff,0xff,0xff,   // 0xffffffc7 == -57
        0xc5, 0xe5,        0xfa,   0b00'100'101,   0xbf,0xff,0xff,0xff,   // 0xffffffbf == -65

        0xc4, 0xe2, 0x7d,  0x17,   0b00'100'101,   0xb6,0xff,0xff,0xff,   // 0xffffffb6 == -74

        0xc5, 0xe4,        0x59,   0b00'100'101,   0xae,0xff,0xff,0xff,   // 0xffffffaf == -82
    });

    test_asm(r, [&](A& a) {
        a.vbroadcastss(A::ymm0,  A::Mem{A::rdi,   0});
        a.vbroadcastss(A::ymm13, A::Mem{A::r14,   7});
        a.vbroadcastss(A::ymm8,  A::Mem{A::rdx, -12});
        a.vbroadcastss(A::ymm8,  A::Mem{A::rdx, 400});

        a.vbroadcastss(A::ymm8,  A::xmm0);
        a.vbroadcastss(A::ymm0,  A::xmm13);
    },{
        /*   VEX    */ /*op*/     /*ModRM*/   /*offset*/
        0xc4,0xe2,0x7d, 0x18,   0b00'000'111,
        0xc4,0x42,0x7d, 0x18,   0b01'101'110,  0x07,
        0xc4,0x62,0x7d, 0x18,   0b01'000'010,  0xf4,
        0xc4,0x62,0x7d, 0x18,   0b10'000'010,  0x90,0x01,0x00,0x00,

        0xc4,0x62,0x7d, 0x18,   0b11'000'000,
        0xc4,0xc2,0x7d, 0x18,   0b11'000'101,
    });

    test_asm(r, [&](A& a) {
        A::Label l;
        a.label(&l);
        a.jne(&l);
        a.jne(&l);
        a.je (&l);
        a.jmp(&l);
        a.jl (&l);
        a.jc (&l);

        a.cmp(A::rdx, 1);
        a.cmp(A::rax, 12);
        a.cmp(A::r14, 2000000000);
    },{
        0x0f,0x85, 0xfa,0xff,0xff,0xff,   // near jne -6 bytes
        0x0f,0x85, 0xf4,0xff,0xff,0xff,   // near jne -12 bytes
        0x0f,0x84, 0xee,0xff,0xff,0xff,   // near je  -18 bytes
        0xe9,      0xe9,0xff,0xff,0xff,   // near jmp -23 bytes
        0x0f,0x8c, 0xe3,0xff,0xff,0xff,   // near jl  -29 bytes
        0x0f,0x82, 0xdd,0xff,0xff,0xff,   // near jc  -35 bytes

        0x48,0x83,0xfa,0x01,
        0x48,0x83,0xf8,0x0c,
        0x49,0x81,0xfe,0x00,0x94,0x35,0x77,
    });

    test_asm(r, [&](A& a) {
        a.vmovups(A::ymm5, A::Mem{A::rsi});
        a.vmovups(A::Mem{A::rsi}, A::ymm5);

        a.vmovups(A::xmm5, A::Mem{A::rsi});
        a.vmovups(A::Mem{A::rsi}, A::xmm5);

        a.vpmovzxwd(A::ymm4, A::Mem{A::rsi});
        a.vpmovzxbd(A::ymm4, A::Mem{A::rsi});

        a.vmovq(A::Mem{A::rdx}, A::xmm15);
    },{
        /*    VEX    */  /*Op*/  /*  ModRM  */
        0xc5,     0xfc,   0x10,  0b00'101'110,
        0xc5,     0xfc,   0x11,  0b00'101'110,

        0xc5,     0xf8,   0x10,  0b00'101'110,
        0xc5,     0xf8,   0x11,  0b00'101'110,

        0xc4,0xe2,0x7d,   0x33,  0b00'100'110,
        0xc4,0xe2,0x7d,   0x31,  0b00'100'110,

        0xc5,     0x79,   0xd6,  0b00'111'010,
    });

    test_asm(r, [&](A& a) {
        a.vmovups(A::ymm5, A::Mem{A::rsp,  0});
        a.vmovups(A::ymm5, A::Mem{A::rsp, 64});
        a.vmovups(A::ymm5, A::Mem{A::rsp,128});

        a.vmovups(A::Mem{A::rsp,  0}, A::ymm5);
        a.vmovups(A::Mem{A::rsp, 64}, A::ymm5);
        a.vmovups(A::Mem{A::rsp,128}, A::ymm5);
    },{
        0xc5,0xfc,0x10,0x2c,0x24,
        0xc5,0xfc,0x10,0x6c,0x24,0x40,
        0xc5,0xfc,0x10,0xac,0x24,0x80,0x00,0x00,0x00,

        0xc5,0xfc,0x11,0x2c,0x24,
        0xc5,0xfc,0x11,0x6c,0x24,0x40,
        0xc5,0xfc,0x11,0xac,0x24,0x80,0x00,0x00,0x00,
    });

    test_asm(r, [&](A& a) {
        a.movzbq(A::rax, A::Mem{A::rsi});   // Low registers for src and dst.
        a.movzbq(A::rax, A::Mem{A::r8,});   // High src register.
        a.movzbq(A::r8 , A::Mem{A::rsi});   // High dst register.
        a.movzbq(A::r8,  A::Mem{A::rsi, 12});
        a.movzbq(A::r8,  A::Mem{A::rsi, 400});

        a.movzwq(A::rax, A::Mem{A::rsi});   // Low registers for src and dst.
        a.movzwq(A::rax, A::Mem{A::r8,});   // High src register.
        a.movzwq(A::r8 , A::Mem{A::rsi});   // High dst register.
        a.movzwq(A::r8,  A::Mem{A::rsi, 12});
        a.movzwq(A::r8,  A::Mem{A::rsi, 400});

        a.vmovd(A::Mem{A::rax}, A::xmm0);
        a.vmovd(A::Mem{A::rax}, A::xmm8);
        a.vmovd(A::Mem{A::r8 }, A::xmm0);

        a.vmovd(A::xmm0, A::Mem{A::rax});
        a.vmovd(A::xmm8, A::Mem{A::rax});
        a.vmovd(A::xmm0, A::Mem{A::r8 });

        a.vmovd(A::xmm0 , A::Mem{A::rax, 0, A::rcx, A::FOUR});
        a.vmovd(A::xmm15, A::Mem{A::rax, 0, A::r8,  A::TWO });
        a.vmovd(A::xmm0 , A::Mem{A::r8 , 0, A::rcx});

        a.vmovd(A::rax, A::xmm0);
        a.vmovd(A::rax, A::xmm8);
        a.vmovd(A::r8 ,  A::xmm0);

        a.vmovd(A::xmm0, A::rax);
        a.vmovd(A::xmm8, A::rax);
        a.vmovd(A::xmm0, A::r8 );

        a.movb(A::Mem{A::rdx}, A::rax);
        a.movb(A::Mem{A::rdx}, A::r8 );
        a.movb(A::Mem{A::r8 }, A::rax);

        a.movb(A::rdx, A::Mem{A::rax});
        a.movb(A::rdx, A::Mem{A::r8 });
        a.movb(A::r8 , A::Mem{A::rax});

        a.movb(A::rdx, 12);
        a.movb(A::rax,  4);
        a.movb(A::r8 , -1);

        a.movb(A::Mem{A::rdx}, 12);
        a.movb(A::Mem{A::rax},  4);
        a.movb(A::Mem{A::r8 }, -1);
    },{
        0x48,0x0f,0xb6,0x06,     // movzbq (%rsi), %rax
        0x49,0x0f,0xb6,0x00,
        0x4c,0x0f,0xb6,0x06,
        0x4c,0x0f,0xb6,0x46, 12,
        0x4c,0x0f,0xb6,0x86, 0x90,0x01,0x00,0x00,

        0x48,0x0f,0xb7,0x06,    // movzwq (%rsi), %rax
        0x49,0x0f,0xb7,0x00,
        0x4c,0x0f,0xb7,0x06,
        0x4c,0x0f,0xb7,0x46, 12,
        0x4c,0x0f,0xb7,0x86, 0x90,0x01,0x00,0x00,

        0xc5,0xf9,0x7e,0x00,
        0xc5,0x79,0x7e,0x00,
        0xc4,0xc1,0x79,0x7e,0x00,

        0xc5,0xf9,0x6e,0x00,
        0xc5,0x79,0x6e,0x00,
        0xc4,0xc1,0x79,0x6e,0x00,

        0xc5,0xf9,0x6e,0x04,0x88,
        0xc4,0x21,0x79,0x6e,0x3c,0x40,
        0xc4,0xc1,0x79,0x6e,0x04,0x08,

        0xc5,0xf9,0x7e,0xc0,
        0xc5,0x79,0x7e,0xc0,
        0xc4,0xc1,0x79,0x7e,0xc0,

        0xc5,0xf9,0x6e,0xc0,
        0xc5,0x79,0x6e,0xc0,
        0xc4,0xc1,0x79,0x6e,0xc0,

        0x48 ,0x88, 0x02,
        0x4c, 0x88, 0x02,
        0x49, 0x88, 0x00,

        0x48 ,0x8a, 0x10,
        0x49, 0x8a, 0x10,
        0x4c, 0x8a, 0x00,

        0x48, 0xc6, 0xc2, 0x0c,
        0x48, 0xc6, 0xc0, 0x04,
        0x49, 0xc6, 0xc0, 0xff,

        0x48, 0xc6, 0x02, 0x0c,
        0x48, 0xc6, 0x00, 0x04,
        0x49, 0xc6, 0x00, 0xff,
    });

    test_asm(r, [&](A& a) {
        a.vpinsrw(A::xmm1, A::xmm8, A::Mem{A::rsi}, 4);   // vpinsrw $4, (%rsi), %xmm8, %xmm1
        a.vpinsrw(A::xmm8, A::xmm1, A::Mem{A::r8 }, 12);  // vpinrsw $12, (%r8), %xmm1, %xmm8

        a.vpinsrb(A::xmm1, A::xmm8, A::Mem{A::rsi}, 4);   // vpinsrb $4, (%rsi), %xmm8, %xmm1
        a.vpinsrb(A::xmm8, A::xmm1, A::Mem{A::r8 }, 12);  // vpinsrb $4, (%rsi), %xmm8, %xmm1

        a.vextracti128(A::xmm1, A::ymm8, 1);  // vextracti128 $1, %ymm8, %xmm1
        a.vextracti128(A::xmm8, A::ymm1, 0);  // vextracti128 $0, %ymm1, %xmm8

        a.vpextrd(A::Mem{A::rsi}, A::xmm8, 3);  // vpextrd  $3, %xmm8, (%rsi)
        a.vpextrd(A::Mem{A::r8 }, A::xmm1, 2);  // vpextrd  $2, %xmm1, (%r8)

        a.vpextrw(A::Mem{A::rsi}, A::xmm8, 7);
        a.vpextrw(A::Mem{A::r8 }, A::xmm1, 15);

        a.vpextrb(A::Mem{A::rsi}, A::xmm8, 7);
        a.vpextrb(A::Mem{A::r8 }, A::xmm1, 15);
    },{
        0xc5,0xb9,      0xc4, 0x0e,  4,
        0xc4,0x41,0x71, 0xc4, 0x00, 12,

        0xc4,0xe3,0x39, 0x20, 0x0e,  4,
        0xc4,0x43,0x71, 0x20, 0x00, 12,

        0xc4,0x63,0x7d,0x39,0xc1, 1,
        0xc4,0xc3,0x7d,0x39,0xc8, 0,

        0xc4,0x63,0x79,0x16,0x06, 3,
        0xc4,0xc3,0x79,0x16,0x08, 2,

        0xc4,0x63,0x79, 0x15, 0x06,  7,
        0xc4,0xc3,0x79, 0x15, 0x08, 15,

        0xc4,0x63,0x79, 0x14, 0x06,  7,
        0xc4,0xc3,0x79, 0x14, 0x08, 15,
    });

    test_asm(r, [&](A& a) {
        a.vpandn(A::ymm3, A::ymm12, A::ymm2);
    },{
        0xc5, 0x9d, 0xdf, 0xda,
    });

    test_asm(r, [&](A& a) {
        A::Label l;
        a.vmovdqa(A::ymm3, A::ymm2);                                // vmovdqa %ymm2         , %ymm3

        a.vmovdqa(A::ymm3, A::Mem{A::rsi});                         // vmovdqa  (%rsi)       , %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::rsp});                         // vmovdqa  (%rsp)       , %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::r11});                         // vmovdqa  (%r11)       , %ymm3

        a.vmovdqa(A::ymm3, A::Mem{A::rsi,  4});                     // vmovdqa 4(%rsi)       , %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::rsp,  4});                     // vmovdqa 4(%rsp)       , %ymm3

        a.vmovdqa(A::ymm3, A::Mem{A::rsi,  4, A::rax, A::EIGHT});   // vmovdqa 4(%rsi,%rax,8), %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::r11,  4, A::rax, A::TWO  });   // vmovdqa 4(%r11,%rax,2), %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::rsi,  4, A::r11, A::FOUR });   // vmovdqa 4(%rsi,%r11,4), %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::rsi,  4, A::r11, A::ONE  });   // vmovdqa 4(%rsi,%r11,1), %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::rsi,  4, A::r11});             // vmovdqa 4(%rsi,%r11)  , %ymm3

        a.vmovdqa(A::ymm3, A::Mem{A::rsi,  64, A::r11});            // vmovdqa  64(%rsi,%r11), %ymm3
        a.vmovdqa(A::ymm3, A::Mem{A::rsi, 128, A::r11});            // vmovdqa 128(%rsi,%r11), %ymm3
        a.vmovdqa(A::ymm3, &l);                                     // vmovdqa  16(%rip)     , %ymm3

        a.vcvttps2dq(A::ymm3, A::ymm2);
        a.vcvtdq2ps (A::ymm3, A::ymm2);
        a.vcvtps2dq (A::ymm3, A::ymm2);
        a.vsqrtps   (A::ymm3, A::ymm2);
        a.label(&l);
    },{
        0xc5,0xfd,0x6f,0xda,

        0xc5,0xfd,0x6f,0x1e,
        0xc5,0xfd,0x6f,0x1c,0x24,
        0xc4,0xc1,0x7d,0x6f,0x1b,

        0xc5,0xfd,0x6f,0x5e,0x04,
        0xc5,0xfd,0x6f,0x5c,0x24,0x04,

        0xc5,0xfd,0x6f,0x5c,0xc6,0x04,
        0xc4,0xc1,0x7d,0x6f,0x5c,0x43,0x04,
        0xc4,0xa1,0x7d,0x6f,0x5c,0x9e,0x04,
        0xc4,0xa1,0x7d,0x6f,0x5c,0x1e,0x04,
        0xc4,0xa1,0x7d,0x6f,0x5c,0x1e,0x04,

        0xc4,0xa1,0x7d,0x6f,0x5c,0x1e,0x40,
        0xc4,0xa1,0x7d,0x6f,0x9c,0x1e,0x80,0x00,0x00,0x00,

        0xc5,0xfd,0x6f,0x1d,0x10,0x00,0x00,0x00,

        0xc5,0xfe,0x5b,0xda,
        0xc5,0xfc,0x5b,0xda,
        0xc5,0xfd,0x5b,0xda,
        0xc5,0xfc,0x51,0xda,
    });

    test_asm(r, [&](A& a) {
        a.vcvtps2ph(A::xmm3, A::ymm2, A::CURRENT);
        a.vcvtps2ph(A::Mem{A::rsi, 32, A::rax, A::EIGHT}, A::ymm5, A::CEIL);

        a.vcvtph2ps(A::ymm15, A::Mem{A::rdi, 12, A::r9, A::ONE});
        a.vcvtph2ps(A::ymm2, A::xmm3);
    },{
        0xc4,0xe3,0x7d,0x1d,0xd3,0x04,
        0xc4,0xe3,0x7d,0x1d,0x6c,0xc6,0x20,0x02,

        0xc4,0x22,0x7d,0x13,0x7c,0x0f,0x0c,
        0xc4,0xe2,0x7d,0x13,0xd3,
    });

    test_asm(r, [&](A& a) {
        a.vgatherdps(A::ymm1 , A::FOUR , A::ymm0 , A::rdi, A::ymm2 );
        a.vgatherdps(A::ymm0 , A::ONE  , A::ymm2 , A::rax, A::ymm1 );
        a.vgatherdps(A::ymm10, A::ONE  , A::ymm2 , A::rax, A::ymm1 );
        a.vgatherdps(A::ymm0 , A::ONE  , A::ymm12, A::rax, A::ymm1 );
        a.vgatherdps(A::ymm0 , A::ONE  , A::ymm2 , A::r9 , A::ymm1 );
        a.vgatherdps(A::ymm0 , A::ONE  , A::ymm2 , A::rax, A::ymm12);
        a.vgatherdps(A::ymm0 , A::EIGHT, A::ymm2 , A::rax, A::ymm12);
    },{
        0xc4,0xe2,0x6d,0x92,0x0c,0x87,
        0xc4,0xe2,0x75,0x92,0x04,0x10,
        0xc4,0x62,0x75,0x92,0x14,0x10,
        0xc4,0xa2,0x75,0x92,0x04,0x20,
        0xc4,0xc2,0x75,0x92,0x04,0x11,
        0xc4,0xe2,0x1d,0x92,0x04,0x10,
        0xc4,0xe2,0x1d,0x92,0x04,0xd0,
    });

    test_asm(r, [&](A& a) {
        a.mov(A::rax, A::Mem{A::rdi,   0});
        a.mov(A::rax, A::Mem{A::rdi,   1});
        a.mov(A::rax, A::Mem{A::rdi, 512});
        a.mov(A::r15, A::Mem{A::r13,  42});
        a.mov(A::rax, A::Mem{A::r13,  42});
        a.mov(A::r15, A::Mem{A::rax,  42});
        a.mov(A::rax, 1);
        a.mov(A::rax, A::rcx);
    },{
        0x48, 0x8b, 0x07,
        0x48, 0x8b, 0x47, 0x01,
        0x48, 0x8b, 0x87, 0x00,0x02,0x00,0x00,
        0x4d, 0x8b, 0x7d, 0x2a,
        0x49, 0x8b, 0x45, 0x2a,
        0x4c, 0x8b, 0x78, 0x2a,
        0x48, 0xc7, 0xc0, 0x01,0x00,0x00,0x00,
        0x48, 0x89, 0xc8,
    });

    // echo "fmul v4.4s, v3.4s, v1.4s" | llvm-mc -show-encoding -arch arm64

    test_asm(r, [&](A& a) {
        a.and16b(A::v4, A::v3, A::v1);
        a.orr16b(A::v4, A::v3, A::v1);
        a.eor16b(A::v4, A::v3, A::v1);
        a.bic16b(A::v4, A::v3, A::v1);
        a.bsl16b(A::v4, A::v3, A::v1);
        a.not16b(A::v4, A::v3);

        a.add4s(A::v4, A::v3, A::v1);
        a.sub4s(A::v4, A::v3, A::v1);
        a.mul4s(A::v4, A::v3, A::v1);

        a.cmeq4s(A::v4, A::v3, A::v1);
        a.cmgt4s(A::v4, A::v3, A::v1);

        a.sub8h(A::v4, A::v3, A::v1);
        a.mul8h(A::v4, A::v3, A::v1);

        a.fadd4s(A::v4, A::v3, A::v1);
        a.fsub4s(A::v4, A::v3, A::v1);
        a.fmul4s(A::v4, A::v3, A::v1);
        a.fdiv4s(A::v4, A::v3, A::v1);
        a.fmin4s(A::v4, A::v3, A::v1);
        a.fmax4s(A::v4, A::v3, A::v1);
        a.fneg4s(A::v4, A::v3);

        a.fmla4s(A::v4, A::v3, A::v1);
        a.fmls4s(A::v4, A::v3, A::v1);

        a.fcmeq4s(A::v4, A::v3, A::v1);
        a.fcmgt4s(A::v4, A::v3, A::v1);
        a.fcmge4s(A::v4, A::v3, A::v1);
    },{
        0x64,0x1c,0x21,0x4e,
        0x64,0x1c,0xa1,0x4e,
        0x64,0x1c,0x21,0x6e,
        0x64,0x1c,0x61,0x4e,
        0x64,0x1c,0x61,0x6e,
        0x64,0x58,0x20,0x6e,

        0x64,0x84,0xa1,0x4e,
        0x64,0x84,0xa1,0x6e,
        0x64,0x9c,0xa1,0x4e,

        0x64,0x8c,0xa1,0x6e,
        0x64,0x34,0xa1,0x4e,

        0x64,0x84,0x61,0x6e,
        0x64,0x9c,0x61,0x4e,

        0x64,0xd4,0x21,0x4e,
        0x64,0xd4,0xa1,0x4e,
        0x64,0xdc,0x21,0x6e,
        0x64,0xfc,0x21,0x6e,
        0x64,0xf4,0xa1,0x4e,
        0x64,0xf4,0x21,0x4e,
        0x64,0xf8,0xa0,0x6e,

        0x64,0xcc,0x21,0x4e,
        0x64,0xcc,0xa1,0x4e,

        0x64,0xe4,0x21,0x4e,
        0x64,0xe4,0xa1,0x6e,
        0x64,0xe4,0x21,0x6e,
    });

    test_asm(r, [&](A& a) {
        a.shl4s(A::v4, A::v3,  0);
        a.shl4s(A::v4, A::v3,  1);
        a.shl4s(A::v4, A::v3,  8);
        a.shl4s(A::v4, A::v3, 16);
        a.shl4s(A::v4, A::v3, 31);

        a.sshr4s(A::v4, A::v3,  1);
        a.sshr4s(A::v4, A::v3,  8);
        a.sshr4s(A::v4, A::v3, 31);

        a.ushr4s(A::v4, A::v3,  1);
        a.ushr4s(A::v4, A::v3,  8);
        a.ushr4s(A::v4, A::v3, 31);

        a.ushr8h(A::v4, A::v3,  1);
        a.ushr8h(A::v4, A::v3,  8);
        a.ushr8h(A::v4, A::v3, 15);
    },{
        0x64,0x54,0x20,0x4f,
        0x64,0x54,0x21,0x4f,
        0x64,0x54,0x28,0x4f,
        0x64,0x54,0x30,0x4f,
        0x64,0x54,0x3f,0x4f,

        0x64,0x04,0x3f,0x4f,
        0x64,0x04,0x38,0x4f,
        0x64,0x04,0x21,0x4f,

        0x64,0x04,0x3f,0x6f,
        0x64,0x04,0x38,0x6f,
        0x64,0x04,0x21,0x6f,

        0x64,0x04,0x1f,0x6f,
        0x64,0x04,0x18,0x6f,
        0x64,0x04,0x11,0x6f,
    });

    test_asm(r, [&](A& a) {
        a.sli4s(A::v4, A::v3,  0);
        a.sli4s(A::v4, A::v3,  1);
        a.sli4s(A::v4, A::v3,  8);
        a.sli4s(A::v4, A::v3, 16);
        a.sli4s(A::v4, A::v3, 31);
    },{
        0x64,0x54,0x20,0x6f,
        0x64,0x54,0x21,0x6f,
        0x64,0x54,0x28,0x6f,
        0x64,0x54,0x30,0x6f,
        0x64,0x54,0x3f,0x6f,
    });

    test_asm(r, [&](A& a) {
        a.scvtf4s (A::v4, A::v3);
        a.fcvtzs4s(A::v4, A::v3);
        a.fcvtns4s(A::v4, A::v3);
    },{
        0x64,0xd8,0x21,0x4e,
        0x64,0xb8,0xa1,0x4e,
        0x64,0xa8,0x21,0x4e,
    });

    test_asm(r, [&](A& a) {
        a.sub (A::sp, A::sp, 32);  // sub   sp, sp, #32
        a.strq(A::v0, A::sp, 1);   // str   q0, [sp, #16]
        a.strq(A::v1, A::sp);      // str   q1, [sp]
        a.strs(A::v0, A::sp, 6);   // str   s0, [sp, #24]
        a.strb(A::v0, A::sp, 47);  // str   b0, [sp, #47]
        a.ldrb(A::v9, A::sp, 42);  // ldr   b9, [sp, #42]
        a.ldrs(A::v7, A::sp, 10);  // ldr   s7, [sp, #40]
        a.ldrq(A::v5, A::sp, 128); // ldr   q5, [sp, #2048]
        a.add (A::sp, A::sp, 32);  // add   sp, sp, #32
    },{
         0xff,0x83,0x00,0xd1,
         0xe0,0x07,0x80,0x3d,
         0xe1,0x03,0x80,0x3d,
         0xe0,0x1b,0x00,0xbd,
         0xe0,0xbf,0x00,0x3d,
         0xe9,0xab,0x40,0x3d,
         0xe7,0x2b,0x40,0xbd,
         0xe5,0x03,0xc2,0x3d,
         0xff,0x83,0x00,0x91,
    });

    test_asm(r, [&](A& a) {
        a.brk(0);
        a.brk(65535);

        a.ret(A::x30);   // Conventional ret using link register.
        a.ret(A::x13);   // Can really return using any register if we like.

        a.add(A::x2, A::x2,  4);
        a.add(A::x3, A::x2, 32);

        a.sub(A::x2, A::x2, 4);
        a.sub(A::x3, A::x2, 32);

        a.subs(A::x2, A::x2,  4);
        a.subs(A::x3, A::x2, 32);

        a.subs(A::xzr, A::x2, 4);  // These are actually the same instruction!
        a.cmp(A::x2, 4);

        A::Label l;
        a.label(&l);
        a.bne(&l);
        a.bne(&l);
        a.blt(&l);
        a.b(&l);
        a.cbnz(A::x2, &l);
        a.cbz(A::x2, &l);
    },{
        0x00,0x00,0x20,0xd4,
        0xe0,0xff,0x3f,0xd4,

        0xc0,0x03,0x5f,0xd6,
        0xa0,0x01,0x5f,0xd6,

        0x42,0x10,0x00,0x91,
        0x43,0x80,0x00,0x91,

        0x42,0x10,0x00,0xd1,
        0x43,0x80,0x00,0xd1,

        0x42,0x10,0x00,0xf1,
        0x43,0x80,0x00,0xf1,

        0x5f,0x10,0x00,0xf1,
        0x5f,0x10,0x00,0xf1,

        0x01,0x00,0x00,0x54,   // b.ne #0
        0xe1,0xff,0xff,0x54,   // b.ne #-4
        0xcb,0xff,0xff,0x54,   // b.lt #-8
        0xae,0xff,0xff,0x54,   // b.al #-12
        0x82,0xff,0xff,0xb5,   // cbnz x2, #-16
        0x62,0xff,0xff,0xb4,   // cbz x2, #-20
    });

    // Can we cbz() to a not-yet-defined label?
    test_asm(r, [&](A& a) {
        A::Label l;
        a.cbz(A::x2, &l);
        a.add(A::x3, A::x2, 32);
        a.label(&l);
        a.ret(A::x30);
    },{
        0x42,0x00,0x00,0xb4,  // cbz x2, #8
        0x43,0x80,0x00,0x91,  // add x3, x2, #32
        0xc0,0x03,0x5f,0xd6,  // ret
    });

    // If we start a label as a backward label,
    // can we redefine it to be a future label?
    // (Not sure this is useful... just want to test it works.)
    test_asm(r, [&](A& a) {
        A::Label l1;
        a.label(&l1);
        a.add(A::x3, A::x2, 32);
        a.cbz(A::x2, &l1);          // This will jump backward... nothing sneaky.

        A::Label l2;                // Start off the same...
        a.label(&l2);
        a.add(A::x3, A::x2, 32);
        a.cbz(A::x2, &l2);          // Looks like this will go backward...
        a.add(A::x2, A::x2, 4);
        a.add(A::x3, A::x2, 32);
        a.label(&l2);               // But no... actually forward!  What a switcheroo!
    },{
        0x43,0x80,0x00,0x91,  // add x3, x2, #32
        0xe2,0xff,0xff,0xb4,  // cbz x2, #-4

        0x43,0x80,0x00,0x91,  // add x3, x2, #32
        0x62,0x00,0x00,0xb4,  // cbz x2, #12
        0x42,0x10,0x00,0x91,  // add x2, x2, #4
        0x43,0x80,0x00,0x91,  // add x3, x2, #32
    });

    // Loading from a label on ARM.
    test_asm(r, [&](A& a) {
        A::Label fore,aft;
        a.label(&fore);
        a.word(0x01234567);
        a.ldrq(A::v1, &fore);
        a.ldrq(A::v2, &aft);
        a.label(&aft);
        a.word(0x76543210);
    },{
        0x67,0x45,0x23,0x01,
        0xe1,0xff,0xff,0x9c,  // ldr q1, #-4
        0x22,0x00,0x00,0x9c,  // ldr q2, #4
        0x10,0x32,0x54,0x76,
    });

    test_asm(r, [&](A& a) {
        a.ldrq(A::v0, A::x8);
        a.strq(A::v0, A::x8);
    },{
        0x00,0x01,0xc0,0x3d,
        0x00,0x01,0x80,0x3d,
    });

    test_asm(r, [&](A& a) {
        a.xtns2h(A::v0, A::v0);
        a.xtnh2b(A::v0, A::v0);
        a.strs  (A::v0, A::x0);

        a.ldrs   (A::v0, A::x0);
        a.uxtlb2h(A::v0, A::v0);
        a.uxtlh2s(A::v0, A::v0);

        a.uminv4s(A::v3, A::v4);
        a.fmovs  (A::x3, A::v4);  // fmov w3,s4
    },{
        0x00,0x28,0x61,0x0e,
        0x00,0x28,0x21,0x0e,
        0x00,0x00,0x00,0xbd,

        0x00,0x00,0x40,0xbd,
        0x00,0xa4,0x08,0x2f,
        0x00,0xa4,0x10,0x2f,

        0x83,0xa8,0xb1,0x6e,
        0x83,0x00,0x26,0x1e,
    });

    test_asm(r, [&](A& a) {
        a.ldrb(A::v0, A::x8);
        a.strb(A::v0, A::x8);
    },{
        0x00,0x01,0x40,0x3d,
        0x00,0x01,0x00,0x3d,
    });

    test_asm(r, [&](A& a) {
        a.tbl(A::v0, A::v1, A::v2);
    },{
        0x20,0x00,0x02,0x4e,
    });
}

DEF_TEST(SkVM_approx_math, r) {
    auto eval = [](int N, float values[], auto fn) {
        skvm::Builder b;
        skvm::Arg inout  = b.varying<float>();

        b.storeF(inout, fn(&b, b.loadF(inout)));

        b.done().eval(N, values);
    };

    auto compare = [r](int N, const float values[], const float expected[]) {
        for (int i = 0; i < N; ++i) {
            REPORTER_ASSERT(r, SkScalarNearlyEqual(values[i], expected[i], 0.001f));
        }
    };

    // log2
    {
        float values[] = {0.25f, 0.5f, 1, 2, 4, 8};
        constexpr int N = SK_ARRAY_COUNT(values);
        eval(N, values, [](skvm::Builder* b, skvm::F32 v) {
            return b->approx_log2(v);
        });
        const float expected[] = {-2, -1, 0, 1, 2, 3};
        compare(N, values, expected);
    }

    // pow2
    {
        float values[] = {-2, -1, 0, 1, 2, 3};
        constexpr int N = SK_ARRAY_COUNT(values);
        eval(N, values, [](skvm::Builder* b, skvm::F32 v) {
            return b->approx_pow2(v);
        });
        const float expected[] = {0.25f, 0.5f, 1, 2, 4, 8};
        compare(N, values, expected);
    }

    // powf -- x^0.5
    {
        float bases[] = {0, 1, 4, 9, 16};
        constexpr int N = SK_ARRAY_COUNT(bases);
        eval(N, bases, [](skvm::Builder* b, skvm::F32 base) {
            return b->approx_powf(base, b->splat(0.5f));
        });
        const float expected[] = {0, 1, 2, 3, 4};
        compare(N, bases, expected);
    }
    // powf -- 3^x
    {
        float exps[] = {-2, -1, 0, 1, 2};
        constexpr int N = SK_ARRAY_COUNT(exps);
        eval(N, exps, [](skvm::Builder* b, skvm::F32 exp) {
            return b->approx_powf(b->splat(3.0f), exp);
        });
        const float expected[] = {1/9.0f, 1/3.0f, 1, 3, 9};
        compare(N, exps, expected);
    }

    auto test = [r](float arg, float expected, float tolerance, auto prog) {
        skvm::Builder b;
        skvm::Arg inout  = b.varying<float>();
        b.storeF(inout, prog(b.loadF(inout)));
        float actual = arg;
        b.done().eval(1, &actual);

        float err = std::abs(actual - expected);

        if (err > tolerance) {
    //        SkDebugf("arg %g, expected %g, actual %g\n", arg, expected, actual);
            REPORTER_ASSERT(r, true);
        }
        return err;
    };

    auto test2 = [r](float arg0, float arg1, float expected, float tolerance, auto prog) {
        skvm::Builder b;
        skvm::Arg in0  = b.varying<float>();
        skvm::Arg in1  = b.varying<float>();
        skvm::Arg out  = b.varying<float>();
        b.storeF(out, prog(b.loadF(in0), b.loadF(in1)));
        float actual;
        b.done().eval(1, &arg0, &arg1, &actual);

        float err = std::abs(actual - expected);

        if (err > tolerance) {
    //        SkDebugf("[%g, %g]: expected %g, actual %g\n", arg0, arg1, expected, actual);
            REPORTER_ASSERT(r, true);
        }
        return err;
    };

    // sine, cosine, tangent
    {
        constexpr float P = SK_ScalarPI;
        constexpr float tol = 0.00175f;
        for (float rad = -5*P; rad <= 5*P; rad += 0.1f) {
            test(rad, sk_float_sin(rad), tol, [](skvm::F32 x) {
                return approx_sin(x);
            });
            test(rad, sk_float_cos(rad), tol, [](skvm::F32 x) {
                return approx_cos(x);
            });
        }

        // Our tangent diverge more as we get near infinities (x near +- Pi/2),
        // so bring in the domain a little.
        constexpr float eps = 0.16f;
        float err = 0;
        for (float rad = -P/2 + eps; rad <= P/2 - eps; rad += 0.01f) {
            err += test(rad, sk_float_tan(rad), tol, [](skvm::F32 x) {
                return approx_tan(x);
            });
            // try again with some multiples of P, to check our periodicity
            test(rad, sk_float_tan(rad), tol, [=](skvm::F32 x) {
                return approx_tan(x + 3*P);
            });
            test(rad, sk_float_tan(rad), tol, [=](skvm::F32 x) {
                return approx_tan(x - 3*P);
            });
        }
        if (0) { SkDebugf("tan error %g\n", err); }
    }

    // asin, acos, atan
    {
        constexpr float tol = 0.00175f;
        float err = 0;
        for (float x = -1; x <= 1; x += 1.0f/64) {
            err += test(x, asin(x), tol, [](skvm::F32 x) {
                return approx_asin(x);
            });
            test(x, acos(x), tol, [](skvm::F32 x) {
                return approx_acos(x);
            });
        }
        if (0) { SkDebugf("asin error %g\n", err); }

        err = 0;
        for (float x = -10; x <= 10; x += 1.0f/16) {
            err += test(x, atan(x), tol, [](skvm::F32 x) {
                return approx_atan(x);
            });
        }
        if (0) { SkDebugf("atan error %g\n", err); }

        for (float y = -3; y <= 3; y += 1) {
            for (float x = -3; x <= 3; x += 1) {
                err += test2(y, x, atan2(y,x), tol, [](skvm::F32 y, skvm::F32 x) {
                    return approx_atan2(y,x);
                });
            }
        }
        if (0) { SkDebugf("atan2 error %g\n", err); }
    }
}

DEF_TEST(SkVM_min_max, r) {
    // min() and max() have subtle behavior when one argument is NaN and
    // the other isn't.  It's not sound to blindly swap their arguments.
    //
    // All backends must behave like std::min() and std::max(), which are
    //
    //    min(x,y) = y<x ? y : x
    //    max(x,y) = x<y ? y : x

    // ±NaN, ±0, ±1, ±inf
    const uint32_t bits[] = {0x7f80'0001, 0xff80'0001, 0x0000'0000, 0x8000'0000,
                             0x3f80'0000, 0xbf80'0000, 0x7f80'0000, 0xff80'0000};

    float f[8];
    memcpy(f, bits, sizeof(bits));

    auto identical = [&](float x, float y) {
        uint32_t X,Y;
        memcpy(&X, &x, 4);
        memcpy(&Y, &y, 4);
        return X == Y;
    };

    // Test min/max with non-constant x, non-constant y.
    // (Whether x and y are varying or uniform shouldn't make any difference.)
    {
        skvm::Builder b;
        {
            skvm::Arg src = b.varying<float>(),
                       mn = b.varying<float>(),
                       mx = b.varying<float>();

            skvm::F32 x = b.loadF(src),
                      y = b.uniformF(b.uniform(), 0);

            b.storeF(mn, b.min(x,y));
            b.storeF(mx, b.max(x,y));
        }

        test_jit_and_interpreter(b.done(), [&](const skvm::Program& program){
            float mn[8], mx[8];
            for (int i = 0; i < 8; i++) {
                // min() and max() everything with f[i].
                program.eval(8, f,mn,mx, &f[i]);

                for (int j = 0; j < 8; j++) {
                    REPORTER_ASSERT(r, identical(mn[j], std::min(f[j], f[i])));
                    REPORTER_ASSERT(r, identical(mx[j], std::max(f[j], f[i])));
                }
            }
        });
    }

    // Test each with constant on the right.
    for (int i = 0; i < 8; i++) {
        skvm::Builder b;
        {
            skvm::Arg src = b.varying<float>(),
                       mn = b.varying<float>(),
                       mx = b.varying<float>();

            skvm::F32 x = b.loadF(src),
                      y = b.splat(f[i]);

            b.storeF(mn, b.min(x,y));
            b.storeF(mx, b.max(x,y));
        }

        test_jit_and_interpreter(b.done(), [&](const skvm::Program& program){
            float mn[8], mx[8];
            program.eval(8, f,mn,mx);
            for (int j = 0; j < 8; j++) {
                REPORTER_ASSERT(r, identical(mn[j], std::min(f[j], f[i])));
                REPORTER_ASSERT(r, identical(mx[j], std::max(f[j], f[i])));
            }
        });
    }

    // Test each with constant on the left.
    for (int i = 0; i < 8; i++) {
        skvm::Builder b;
        {
            skvm::Arg src = b.varying<float>(),
                       mn = b.varying<float>(),
                       mx = b.varying<float>();

            skvm::F32 x = b.splat(f[i]),
                      y = b.loadF(src);

            b.storeF(mn, b.min(x,y));
            b.storeF(mx, b.max(x,y));
        }

        test_jit_and_interpreter(b.done(), [&](const skvm::Program& program){
            float mn[8], mx[8];
            program.eval(8, f,mn,mx);
            for (int j = 0; j < 8; j++) {
                REPORTER_ASSERT(r, identical(mn[j], std::min(f[i], f[j])));
                REPORTER_ASSERT(r, identical(mx[j], std::max(f[i], f[j])));
            }
        });
    }
}

DEF_TEST(SkVM_halfs, r) {
    const uint16_t hs[] = {0x0000,0x3800,0x3c00,0x4000,
                           0xc400,0xb800,0xbc00,0xc000};
    const float fs[] = {+0.0f,+0.5f,+1.0f,+2.0f,
                        -4.0f,-0.5f,-1.0f,-2.0f};
    {
        skvm::Builder b;
        skvm::Arg src = b.varying<uint16_t>(),
                  dst = b.varying<float>();
        b.storeF(dst, b.from_half(b.load16(src)));

        test_jit_and_interpreter(b.done(), [&](const skvm::Program& program){
            float dst[8];
            program.eval(8, hs, dst);
            for (int i = 0; i < 8; i++) {
                REPORTER_ASSERT(r, dst[i] == fs[i]);
            }
        });
    }
    {
        skvm::Builder b;
        skvm::Arg src = b.varying<float>(),
                  dst = b.varying<uint16_t>();
        b.store16(dst, b.to_half(b.loadF(src)));

        test_jit_and_interpreter(b.done(), [&](const skvm::Program& program){
            uint16_t dst[8];
            program.eval(8, fs, dst);
            for (int i = 0; i < 8; i++) {
                REPORTER_ASSERT(r, dst[i] == hs[i]);
            }
        });
    }
}