additional skslc vector optimizations
Bug: skia:
Change-Id: I845d0952c281835a630882ae4026277c93ccf542
Reviewed-on: https://skia-review.googlesource.com/14406
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
diff --git a/src/sksl/SkSLCompiler.cpp b/src/sksl/SkSLCompiler.cpp
index f5f2151..f417626 100644
--- a/src/sksl/SkSLCompiler.cpp
+++ b/src/sksl/SkSLCompiler.cpp
@@ -396,14 +396,27 @@
}
/**
- * Returns true if the expression is a constant numeric literal with the specified value.
+ * Returns true if the expression is a constant numeric literal with the specified value, or a
+ * constant vector with all elements equal to the specified value.
*/
-bool is_constant(Expression& expr, double value) {
+bool is_constant(const Expression& expr, double value) {
switch (expr.fKind) {
case Expression::kIntLiteral_Kind:
return ((IntLiteral&) expr).fValue == value;
case Expression::kFloatLiteral_Kind:
return ((FloatLiteral&) expr).fValue == value;
+ case Expression::kConstructor_Kind: {
+ Constructor& c = (Constructor&) expr;
+ if (c.fType.kind() == Type::kVector_Kind && c.isConstant()) {
+ for (int i = 0; i < c.fType.columns(); ++i) {
+ if (!is_constant(c.getVecComponent(i), value)) {
+ return false;
+ }
+ }
+ return true;
+ }
+ return false;
+ }
default:
return false;
}
@@ -417,6 +430,7 @@
std::vector<BasicBlock::Node>::iterator* iter,
bool* outUpdated,
bool* outNeedsRescan) {
+ ASSERT((*(*iter)->expression())->fKind == Expression::kBinary_Kind);
*outUpdated = true;
if (!try_replace_expression(b, iter, &((BinaryExpression&) **(*iter)->expression()).fRight)) {
*outNeedsRescan = true;
@@ -431,12 +445,95 @@
std::vector<BasicBlock::Node>::iterator* iter,
bool* outUpdated,
bool* outNeedsRescan) {
+ ASSERT((*(*iter)->expression())->fKind == Expression::kBinary_Kind);
*outUpdated = true;
if (!try_replace_expression(b, iter, &((BinaryExpression&) **(*iter)->expression()).fLeft)) {
*outNeedsRescan = true;
}
}
+/**
+ * Constructs the specified type using a single argument.
+ */
+static std::unique_ptr<Expression> construct(const Type& type, std::unique_ptr<Expression> v) {
+ std::vector<std::unique_ptr<Expression>> args;
+ args.push_back(std::move(v));
+ auto result = std::unique_ptr<Expression>(new Constructor(Position(), type, std::move(args)));
+ return result;
+}
+
+/**
+ * Used in the implementations of vectorize_left and vectorize_right. Given a vector type and an
+ * expression x, deletes the expression pointed to by iter and replaces it with <type>(x).
+ */
+static void vectorize(BasicBlock* b,
+ std::vector<BasicBlock::Node>::iterator* iter,
+ const Type& type,
+ std::unique_ptr<Expression>* otherExpression,
+ bool* outUpdated,
+ bool* outNeedsRescan) {
+ ASSERT((*(*iter)->expression())->fKind == Expression::kBinary_Kind);
+ ASSERT(type.kind() == Type::kVector_Kind);
+ ASSERT((*otherExpression)->fType.kind() == Type::kScalar_Kind);
+ *outUpdated = true;
+ std::unique_ptr<Expression>* target = (*iter)->expression();
+ if (!b->tryRemoveExpression(iter)) {
+ *target = construct(type, std::move(*otherExpression));
+ *outNeedsRescan = true;
+ } else {
+ *target = construct(type, std::move(*otherExpression));
+ if (!b->tryInsertExpression(iter, target)) {
+ *outNeedsRescan = true;
+ }
+ }
+}
+
+/**
+ * Given a binary expression of the form x <op> vec<n>(y), deletes the right side and vectorizes the
+ * left to yield vec<n>(x).
+ */
+static void vectorize_left(BasicBlock* b,
+ std::vector<BasicBlock::Node>::iterator* iter,
+ bool* outUpdated,
+ bool* outNeedsRescan) {
+ BinaryExpression& bin = (BinaryExpression&) **(*iter)->expression();
+ vectorize(b, iter, bin.fRight->fType, &bin.fLeft, outUpdated, outNeedsRescan);
+}
+
+/**
+ * Given a binary expression of the form vec<n>(x) <op> y, deletes the left side and vectorizes the
+ * right to yield vec<n>(y).
+ */
+static void vectorize_right(BasicBlock* b,
+ std::vector<BasicBlock::Node>::iterator* iter,
+ bool* outUpdated,
+ bool* outNeedsRescan) {
+ BinaryExpression& bin = (BinaryExpression&) **(*iter)->expression();
+ vectorize(b, iter, bin.fLeft->fType, &bin.fRight, outUpdated, outNeedsRescan);
+}
+
+// Mark that an expression which we were writing to is no longer being written to
+void clear_write(const Expression& expr) {
+ switch (expr.fKind) {
+ case Expression::kVariableReference_Kind: {
+ ((VariableReference&) expr).setRefKind(VariableReference::kRead_RefKind);
+ break;
+ }
+ case Expression::kFieldAccess_Kind:
+ clear_write(*((FieldAccess&) expr).fBase);
+ break;
+ case Expression::kSwizzle_Kind:
+ clear_write(*((Swizzle&) expr).fBase);
+ break;
+ case Expression::kIndex_Kind:
+ clear_write(*((IndexExpression&) expr).fBase);
+ break;
+ default:
+ ABORT("shouldn't be writing to this kind of expression\n");
+ break;
+ }
+}
+
void Compiler::simplifyExpression(DefinitionMap& definitions,
BasicBlock& b,
std::vector<BasicBlock::Node>::iterator* iter,
@@ -485,30 +582,148 @@
case Expression::kBinary_Kind: {
// collapse useless expressions like x * 1 or x + 0
BinaryExpression* bin = (BinaryExpression*) expr;
+ if (((bin->fLeft->fType.kind() != Type::kScalar_Kind) &&
+ (bin->fLeft->fType.kind() != Type::kVector_Kind)) ||
+ ((bin->fRight->fType.kind() != Type::kScalar_Kind) &&
+ (bin->fRight->fType.kind() != Type::kVector_Kind))) {
+ break;
+ }
switch (bin->fOperator) {
case Token::STAR:
if (is_constant(*bin->fLeft, 1)) {
- delete_left(&b, iter, outUpdated, outNeedsRescan);
+ if (bin->fLeft->fType.kind() == Type::kVector_Kind &&
+ bin->fRight->fType.kind() == Type::kScalar_Kind) {
+ // vec4(1) * x -> vec4(x)
+ vectorize_right(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // 1 * x -> x
+ // 1 * vec4(x) -> vec4(x)
+ // vec4(1) * vec4(x) -> vec4(x)
+ delete_left(&b, iter, outUpdated, outNeedsRescan);
+ }
+ }
+ else if (is_constant(*bin->fLeft, 0)) {
+ if (bin->fLeft->fType.kind() == Type::kScalar_Kind &&
+ bin->fRight->fType.kind() == Type::kVector_Kind) {
+ // 0 * vec4(x) -> vec4(0)
+ vectorize_left(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // 0 * x -> 0
+ // vec4(0) * x -> vec4(0)
+ // vec4(0) * vec4(x) -> vec4(0)
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
}
else if (is_constant(*bin->fRight, 1)) {
- delete_right(&b, iter, outUpdated, outNeedsRescan);
+ if (bin->fLeft->fType.kind() == Type::kScalar_Kind &&
+ bin->fRight->fType.kind() == Type::kVector_Kind) {
+ // x * vec4(1) -> vec4(x)
+ vectorize_left(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // x * 1 -> x
+ // vec4(x) * 1 -> vec4(x)
+ // vec4(x) * vec4(1) -> vec4(x)
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
+ }
+ else if (is_constant(*bin->fRight, 0)) {
+ if (bin->fLeft->fType.kind() == Type::kVector_Kind &&
+ bin->fRight->fType.kind() == Type::kScalar_Kind) {
+ // vec4(x) * 0 -> vec4(0)
+ vectorize_right(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // x * 0 -> 0
+ // x * vec4(0) -> vec4(0)
+ // vec4(x) * vec4(0) -> vec4(0)
+ delete_left(&b, iter, outUpdated, outNeedsRescan);
+ }
}
break;
case Token::PLUS:
if (is_constant(*bin->fLeft, 0)) {
- delete_left(&b, iter, outUpdated, outNeedsRescan);
- }
- if (is_constant(*bin->fRight, 0)) {
- delete_right(&b, iter, outUpdated, outNeedsRescan);
+ if (bin->fLeft->fType.kind() == Type::kVector_Kind &&
+ bin->fRight->fType.kind() == Type::kScalar_Kind) {
+ // vec4(0) + x -> vec4(x)
+ vectorize_right(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // 0 + x -> x
+ // 0 + vec4(x) -> vec4(x)
+ // vec4(0) + vec4(x) -> vec4(x)
+ delete_left(&b, iter, outUpdated, outNeedsRescan);
+ }
+ } else if (is_constant(*bin->fRight, 0)) {
+ if (bin->fLeft->fType.kind() == Type::kScalar_Kind &&
+ bin->fRight->fType.kind() == Type::kVector_Kind) {
+ // x + vec4(0) -> vec4(x)
+ vectorize_left(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // x + 0 -> x
+ // vec4(x) + 0 -> vec4(x)
+ // vec4(x) + vec4(0) -> vec4(x)
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
}
break;
case Token::MINUS:
if (is_constant(*bin->fRight, 0)) {
- delete_right(&b, iter, outUpdated, outNeedsRescan);
+ if (bin->fLeft->fType.kind() == Type::kScalar_Kind &&
+ bin->fRight->fType.kind() == Type::kVector_Kind) {
+ // x - vec4(0) -> vec4(x)
+ vectorize_left(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // x - 0 -> x
+ // vec4(x) - 0 -> vec4(x)
+ // vec4(x) - vec4(0) -> vec4(x)
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
}
break;
case Token::SLASH:
if (is_constant(*bin->fRight, 1)) {
+ if (bin->fLeft->fType.kind() == Type::kScalar_Kind &&
+ bin->fRight->fType.kind() == Type::kVector_Kind) {
+ // x / vec4(1) -> vec4(x)
+ vectorize_left(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // x / 1 -> x
+ // vec4(x) / 1 -> vec4(x)
+ // vec4(x) / vec4(1) -> vec4(x)
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
+ } else if (is_constant(*bin->fLeft, 0)) {
+ if (bin->fLeft->fType.kind() == Type::kScalar_Kind &&
+ bin->fRight->fType.kind() == Type::kVector_Kind) {
+ // 0 / vec4(x) -> vec4(0)
+ vectorize_left(&b, iter, outUpdated, outNeedsRescan);
+ } else {
+ // 0 / x -> 0
+ // vec4(0) / x -> vec4(0)
+ // vec4(0) / vec4(x) -> vec4(0)
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
+ }
+ break;
+ case Token::PLUSEQ:
+ if (is_constant(*bin->fRight, 0)) {
+ clear_write(*bin->fLeft);
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
+ break;
+ case Token::MINUSEQ:
+ if (is_constant(*bin->fRight, 0)) {
+ clear_write(*bin->fLeft);
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
+ break;
+ case Token::STAREQ:
+ if (is_constant(*bin->fRight, 1)) {
+ clear_write(*bin->fLeft);
+ delete_right(&b, iter, outUpdated, outNeedsRescan);
+ }
+ break;
+ case Token::SLASHEQ:
+ if (is_constant(*bin->fRight, 1)) {
+ clear_write(*bin->fLeft);
delete_right(&b, iter, outUpdated, outNeedsRescan);
}
break;