diff options
| author |  Ethan Nicholas <ethannicholas@google.com> | 2018-01-23 10:31:56 -0500 |
|---|---|---|
| committer |  Skia Commit-Bot <skia-commit-bot@chromium.org> | 2018-01-23 18:18:37 +0000 |
| commit | 08dae924f63cd00153ec365074ad498dbb8ab5ab (patch) | |
| tree | 053787481fddf423577c028a83240b6905afc4a4 /src | |
| parent | d8327a8c8bad870112b574c4533270370f5c1ccf (diff) | |
Fixed a few spots where SkSL optimizer was not respecting side effects
This was affecting expressions such as 0 * float4(<expr>), which would
be collapsed down to float4(0) - in some cases even if <expr> had side
effects. This is obviously incorrect no matter what, but to make matters
worse it could lead to a use-after-free when we eliminated an assignment
which we were tracking as the current definition of a variable.
Bug: skia:7467
Change-Id: I91ba154c57dad9cadf36b6062bec3211557248e0
Reviewed-on: https://skia-review.googlesource.com/98704
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/sksl/SkSLCompiler.cpp | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/src/sksl/SkSLCompiler.cpp b/src/sksl/SkSLCompiler.cpp index 17a205ced5..7589da98ee 100644 --- a/src/sksl/SkSLCompiler.cpp +++ b/src/sksl/SkSLCompiler.cpp @@ -713,7 +713,8 @@ void Compiler::simplifyExpression(DefinitionMap& definitions, } else if (is_constant(*bin->fLeft, 0)) { if (bin->fLeft->fType.kind() == Type::kScalar_Kind && - bin->fRight->fType.kind() == Type::kVector_Kind) { + bin->fRight->fType.kind() == Type::kVector_Kind && + !bin->fRight->hasSideEffects()) { // 0 * float4(x) -> float4(0) vectorize_left(&b, iter, outUpdated, outNeedsRescan); } else { @@ -739,7 +740,8 @@ void Compiler::simplifyExpression(DefinitionMap& definitions, } else if (is_constant(*bin->fRight, 0)) { if (bin->fLeft->fType.kind() == Type::kVector_Kind && - bin->fRight->fType.kind() == Type::kScalar_Kind) { + bin->fRight->fType.kind() == Type::kScalar_Kind && + !bin->fLeft->hasSideEffects()) { // float4(x) * 0 -> float4(0) vectorize_right(&b, iter, outUpdated, outNeedsRescan); } else { @@ -805,7 +807,8 @@ void Compiler::simplifyExpression(DefinitionMap& definitions, } } else if (is_constant(*bin->fLeft, 0)) { if (bin->fLeft->fType.kind() == Type::kScalar_Kind && - bin->fRight->fType.kind() == Type::kVector_Kind) { + bin->fRight->fType.kind() == Type::kVector_Kind && + !bin->fRight->hasSideEffects()) { // 0 / float4(x) -> float4(0) vectorize_left(&b, iter, outUpdated, outNeedsRescan); } else { |