[X86] Fix Windows `i1 zeroext` conventions to use i8 instead of i32

Summary:
Re-lands r328386 and r328443, reverting r328482.

Incorporates fixes from @mstorsjo in D44876 (thanks!) so that small
parameters in i8 and i16 do not end up in the SysV register parameters
(EDI, ESI, etc).

I added tests for how we receive small parameters, since that is the
important part. It's always safe to store more bytes than will be read,
but the assumptions you make when loading them are what really matter.

I also tested this by self-hosting clang and it passed tests on win64.

Reviewers: mstorsjo, hans

Subscribers: hiraditya, mstorsjo, llvm-commits

Differential Revision: https://reviews.llvm.org/D44900

llvm-svn: 328570
diff --git a/llvm/test/CodeGen/X86/avx512-intel-ocl.ll b/llvm/test/CodeGen/X86/avx512-intel-ocl.ll
index 61718fb..defedd2 100644
--- a/llvm/test/CodeGen/X86/avx512-intel-ocl.ll
+++ b/llvm/test/CodeGen/X86/avx512-intel-ocl.ll
@@ -420,6 +420,7 @@
 ; WIN64-KNL-NEXT:    subq $40, %rsp
 ; WIN64-KNL-NEXT:    .seh_stackalloc 40
 ; WIN64-KNL-NEXT:    .seh_endprologue
+; WIN64-KNL-NEXT:    # kill: def $dx killed $dx def $edx
 ; WIN64-KNL-NEXT:    vmovaps (%rcx), %zmm0
 ; WIN64-KNL-NEXT:    kmovw %edx, %k1
 ; WIN64-KNL-NEXT:    callq func_float16_mask
@@ -435,6 +436,7 @@
 ; WIN64-SKX-NEXT:    subq $40, %rsp
 ; WIN64-SKX-NEXT:    .seh_stackalloc 40
 ; WIN64-SKX-NEXT:    .seh_endprologue
+; WIN64-SKX-NEXT:    # kill: def $dx killed $dx def $edx
 ; WIN64-SKX-NEXT:    vmovaps (%rcx), %zmm0
 ; WIN64-SKX-NEXT:    kmovd %edx, %k1
 ; WIN64-SKX-NEXT:    callq func_float16_mask
diff --git a/llvm/test/CodeGen/X86/h-registers-0.ll b/llvm/test/CodeGen/X86/h-registers-0.ll
index 5f459c3..dfd79f3 100644
--- a/llvm/test/CodeGen/X86/h-registers-0.ll
+++ b/llvm/test/CodeGen/X86/h-registers-0.ll
@@ -98,7 +98,8 @@
 ; X86-64: movzbl %ah, %eax
 
 ; WIN64-LABEL:  qux16:
-; WIN64:  movzbl %ch, %eax
+; WIN64:  movzwl  %cx, %eax
+; WIN64:  shrl    $8, %eax
 
 ; X86-32-LABEL: qux16:
 ; X86-32: movzbl %ah, %eax
diff --git a/llvm/test/CodeGen/X86/test-shrink.ll b/llvm/test/CodeGen/X86/test-shrink.ll
index e44233f..5a59814 100644
--- a/llvm/test/CodeGen/X86/test-shrink.ll
+++ b/llvm/test/CodeGen/X86/test-shrink.ll
@@ -186,6 +186,7 @@
 ; CHECK-WIN32-64-LABEL: g16xh:
 ; CHECK-WIN32-64:       # %bb.0:
 ; CHECK-WIN32-64-NEXT:    subq $40, %rsp
+; CHECK-WIN32-64-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN32-64-NEXT:    testl $2048, %ecx # imm = 0x800
 ; CHECK-WIN32-64-NEXT:    jne .LBB4_2
 ; CHECK-WIN32-64-NEXT:  # %bb.1: # %yes
@@ -228,6 +229,7 @@
 ; CHECK-WIN32-64-LABEL: g16xl:
 ; CHECK-WIN32-64:       # %bb.0:
 ; CHECK-WIN32-64-NEXT:    subq $40, %rsp
+; CHECK-WIN32-64-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN32-64-NEXT:    testb $8, %cl
 ; CHECK-WIN32-64-NEXT:    jne .LBB5_2
 ; CHECK-WIN32-64-NEXT:  # %bb.1: # %yes
@@ -497,6 +499,7 @@
 ; CHECK-WIN32-64-LABEL: truncand32:
 ; CHECK-WIN32-64:       # %bb.0:
 ; CHECK-WIN32-64-NEXT:    subq $40, %rsp
+; CHECK-WIN32-64-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN32-64-NEXT:    testl $2049, %ecx # imm = 0x801
 ; CHECK-WIN32-64-NEXT:    je .LBB11_1
 ; CHECK-WIN32-64-NEXT:  # %bb.2: # %no
@@ -543,6 +546,7 @@
 ; CHECK-WIN32-64-LABEL: testw:
 ; CHECK-WIN32-64:       # %bb.0:
 ; CHECK-WIN32-64-NEXT:    subq $40, %rsp
+; CHECK-WIN32-64-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN32-64-NEXT:    testw $2049, %cx # imm = 0x801
 ; CHECK-WIN32-64-NEXT:    jne .LBB12_2
 ; CHECK-WIN32-64-NEXT:  # %bb.1: # %yes
diff --git a/llvm/test/CodeGen/X86/vec_cast.ll b/llvm/test/CodeGen/X86/vec_cast.ll
index e6e5982..f6b1ac1 100644
--- a/llvm/test/CodeGen/X86/vec_cast.ll
+++ b/llvm/test/CodeGen/X86/vec_cast.ll
@@ -37,6 +37,9 @@
 ;
 ; CHECK-WIN-LABEL: b:
 ; CHECK-WIN:       # %bb.0:
+; CHECK-WIN-NEXT:    # kill: def $r8w killed $r8w def $r8d
+; CHECK-WIN-NEXT:    # kill: def $dx killed $dx def $edx
+; CHECK-WIN-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN-NEXT:    movd %ecx, %xmm0
 ; CHECK-WIN-NEXT:    pinsrw $1, %edx, %xmm0
 ; CHECK-WIN-NEXT:    pinsrw $2, %r8d, %xmm0
@@ -58,6 +61,7 @@
 ;
 ; CHECK-WIN-LABEL: c:
 ; CHECK-WIN:       # %bb.0:
+; CHECK-WIN-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN-NEXT:    movd %ecx, %xmm0
 ; CHECK-WIN-NEXT:    pshuflw {{.*#+}} xmm0 = xmm0[0,0,2,1,4,5,6,7]
 ; CHECK-WIN-NEXT:    psrad $16, %xmm0
@@ -100,6 +104,9 @@
 ;
 ; CHECK-WIN-LABEL: e:
 ; CHECK-WIN:       # %bb.0:
+; CHECK-WIN-NEXT:    # kill: def $r8w killed $r8w def $r8d
+; CHECK-WIN-NEXT:    # kill: def $dx killed $dx def $edx
+; CHECK-WIN-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN-NEXT:    movd %ecx, %xmm0
 ; CHECK-WIN-NEXT:    pinsrw $1, %edx, %xmm0
 ; CHECK-WIN-NEXT:    pinsrw $2, %r8d, %xmm0
@@ -121,6 +128,7 @@
 ;
 ; CHECK-WIN-LABEL: f:
 ; CHECK-WIN:       # %bb.0:
+; CHECK-WIN-NEXT:    # kill: def $cx killed $cx def $ecx
 ; CHECK-WIN-NEXT:    movd %ecx, %xmm0
 ; CHECK-WIN-NEXT:    pxor %xmm1, %xmm1
 ; CHECK-WIN-NEXT:    punpcklwd {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1],xmm0[2],xmm1[2],xmm0[3],xmm1[3]
diff --git a/llvm/test/CodeGen/X86/win-smallparams.ll b/llvm/test/CodeGen/X86/win-smallparams.ll
new file mode 100644
index 0000000..93b528a
--- /dev/null
+++ b/llvm/test/CodeGen/X86/win-smallparams.ll
@@ -0,0 +1,67 @@
+; When we accept small parameters on Windows, make sure we do not assume they
+; are zero or sign extended in memory or in registers.
+
+; RUN: llc < %s -mtriple=x86_64-windows-msvc | FileCheck %s --check-prefix=WIN64
+; RUN: llc < %s -mtriple=x86_64-windows-gnu | FileCheck %s --check-prefix=WIN64
+; RUN: llc < %s -mtriple=i686-windows-msvc | FileCheck %s --check-prefix=WIN32
+; RUN: llc < %s -mtriple=i686-windows-gnu | FileCheck %s --check-prefix=WIN32
+
+define void @call() {
+entry:
+  %rv = call i32 @manyargs(i8 1, i16 2, i8 3, i16 4, i8 5, i16 6)
+  ret void
+}
+
+define i32 @manyargs(i8 %a, i16 %b, i8 %c, i16 %d, i8 %e, i16 %f) {
+entry:
+  %aa = sext i8 %a to i32
+  %bb = sext i16 %b to i32
+  %cc = zext i8 %c to i32
+  %dd = zext i16 %d to i32
+  %ee = zext i8 %e to i32
+  %ff = zext i16 %f to i32
+  %t0 = add i32 %aa, %bb
+  %t1 = add i32 %t0, %cc
+  %t2 = add i32 %t1, %dd
+  %t3 = add i32 %t2, %ee
+  %t4 = add i32 %t3, %ff
+  ret i32 %t4
+}
+
+; WIN64-LABEL: call:
+; WIN64-DAG: movw $6, 40(%rsp)
+; WIN64-DAG: movb $5, 32(%rsp)
+; WIN64-DAG: movb $1, %cl
+; WIN64-DAG: movw $2, %dx
+; WIN64-DAG: movb $3, %r8b
+; WIN64-DAG: movw $4, %r9w
+; WIN64: callq manyargs
+
+; WIN64-LABEL: manyargs:
+; WIN64-DAG: movsbl %cl,
+; WIN64-DAG: movswl %dx,
+; WIN64-DAG: movzbl %r8b,
+; WIN64-DAG: movzwl %r9w,
+; WIN64-DAG: movzbl 40(%rsp),
+; WIN64-DAG: movzwl 48(%rsp),
+; WIN64: retq
+
+
+; WIN32-LABEL: _call:
+; WIN32: pushl $6
+; WIN32: pushl $5
+; WIN32: pushl $4
+; WIN32: pushl $3
+; WIN32: pushl $2
+; WIN32: pushl $1
+; WIN32: calll _manyargs
+
+; WIN32-LABEL: _manyargs:
+; WIN32-DAG: movsbl 4(%esp),
+; WIN32-DAG: movswl 8(%esp),
+; WIN32-DAG: movzbl 12(%esp),
+; WIN32-DAG: movzwl 16(%esp),
+; WIN32-DAG: movzbl 20(%esp),
+; WIN32-DAG: movzwl 24(%esp),
+; WIN32: retl
+
diff --git a/llvm/test/CodeGen/X86/win32-bool.ll b/llvm/test/CodeGen/X86/win32-bool.ll
new file mode 100644
index 0000000..53607ea
--- /dev/null
+++ b/llvm/test/CodeGen/X86/win32-bool.ll
@@ -0,0 +1,33 @@
+; RUN: llc < %s -mtriple=i686-windows-msvc | FileCheck %s
+; RUN: llc < %s -mtriple=i686-windows-gnu | FileCheck %s
+
+define x86_fastcallcc i32 @pass_fast_bool(i1 inreg zeroext %b) {
+entry:
+  %cond = select i1 %b, i32 66, i32 0
+  ret i32 %cond
+}
+
+; CHECK-LABEL: @pass_fast_bool@4:
+; CHECK-DAG: testb %cl, %cl
+; CHECK-DAG: movl    $66,
+; CHECK:     retl
+
+define x86_vectorcallcc i32 @pass_vector_bool(i1 inreg zeroext %b) {
+entry:
+  %cond = select i1 %b, i32 66, i32 0
+  ret i32 %cond
+}
+
+; CHECK-LABEL: pass_vector_bool@@4:
+; CHECK-DAG: testb %cl, %cl
+; CHECK-DAG: movl    $66,
+; CHECK:     retl
+
+define zeroext i1 @ret_true() {
+entry:
+  ret i1 true
+}
+
+; CHECK-LABEL: ret_true:
+; CHECK:     movb $1, %al
+; CHECK:     retl
diff --git a/llvm/test/CodeGen/X86/win64-bool.ll b/llvm/test/CodeGen/X86/win64-bool.ll
new file mode 100644
index 0000000..cb77c7e
--- /dev/null
+++ b/llvm/test/CodeGen/X86/win64-bool.ll
@@ -0,0 +1,23 @@
+; RUN: llc < %s -mtriple=x86_64-windows-msvc | FileCheck %s --check-prefix=CHECK
+; RUN: llc < %s -mtriple=x86_64-windows-gnu | FileCheck %s --check-prefix=CHECK
+
+define i32 @pass_bool(i1 zeroext %b) {
+entry:
+  %cond = select i1 %b, i32 66, i32 0
+  ret i32 %cond
+}
+
+; CHECK-LABEL: pass_bool:
+; CHECK-DAG: testb %cl, %cl
+; CHECK-DAG: movl    $66,
+; CHECK:     cmovel {{.*}}, %eax
+; CHECK:     retq
+
+define zeroext i1 @ret_true() {
+entry:
+  ret i1 true
+}
+
+; CHECK-LABEL: ret_true:
+; CHECK:     movb $1, %al
+; CHECK:     retq
diff --git a/llvm/test/CodeGen/X86/xor.ll b/llvm/test/CodeGen/X86/xor.ll
index 6f0f0df..f73fdb2 100644
--- a/llvm/test/CodeGen/X86/xor.ll
+++ b/llvm/test/CodeGen/X86/xor.ll
@@ -167,6 +167,8 @@
 ;
 ; X64-WIN-LABEL: test5:
 ; X64-WIN:       # %bb.0: # %entry
+; X64-WIN-NEXT:    # kill: def $dx killed $dx def $edx
+; X64-WIN-NEXT:    # kill: def $cx killed $cx def $ecx
 ; X64-WIN-NEXT:    .p2align 4, 0x90
 ; X64-WIN-NEXT:  .LBB4_1: # %bb
 ; X64-WIN-NEXT:    # =>This Inner Loop Header: Depth=1
@@ -427,7 +429,8 @@
 ;
 ; X64-WIN-LABEL: PR17487:
 ; X64-WIN:       # %bb.0:
-; X64-WIN-NEXT:    movd %ecx, %xmm0
+; X64-WIN-NEXT:    movzbl %cl, %eax
+; X64-WIN-NEXT:    movd %eax, %xmm0
 ; X64-WIN-NEXT:    pshufd {{.*#+}} xmm0 = xmm0[0,1,0,1]
 ; X64-WIN-NEXT:    pandn __xmm@{{.*}}(%rip), %xmm0
 ; X64-WIN-NEXT:    pshufd {{.*#+}} xmm0 = xmm0[2,3,0,1]