diff options
| -rw-r--r-- | js/src/jit/IonAnalysis.cpp | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/js/src/jit/IonAnalysis.cpp b/js/src/jit/IonAnalysis.cpp index b163d5818..d255c32a8 100644 --- a/js/src/jit/IonAnalysis.cpp +++ b/js/src/jit/IonAnalysis.cpp @@ -3127,6 +3127,15 @@ ExtractMathSpace(MDefinition* ins) MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Unknown TruncateKind"); } +static bool MonotoneAdd(int32_t lhs, int32_t rhs) { + return (lhs >= 0 && rhs >= 0) || (lhs <= 0 && rhs <= 0); +} + +static bool MonotoneSub(int32_t lhs, int32_t rhs) { + return (lhs >= 0 && rhs <= 0) || (lhs <= 0 && rhs >= 0); +} + + // Extract a linear sum from ins, if possible (otherwise giving the sum 'ins + 0'). SimpleLinearSum jit::ExtractLinearSum(MDefinition* ins, MathSpace space) @@ -3168,10 +3177,12 @@ jit::ExtractLinearSum(MDefinition* ins, MathSpace space) // Check if this is of the form <SUM> + n or n + <SUM>. if (ins->isAdd()) { int32_t constant; - if (space == MathSpace::Modulo) + if (space == MathSpace::Modulo) { constant = lsum.constant + rsum.constant; - else if (!SafeAdd(lsum.constant, rsum.constant, &constant)) + } else if (!SafeAdd(lsum.constant, rsum.constant, &constant) || + !MonotoneAdd(lsum.constant, rsum.constant)) { return SimpleLinearSum(ins, 0); + } return SimpleLinearSum(lsum.term ? lsum.term : rsum.term, constant); } @@ -3179,10 +3190,12 @@ jit::ExtractLinearSum(MDefinition* ins, MathSpace space) // Check if this is of the form <SUM> - n. if (lsum.term) { int32_t constant; - if (space == MathSpace::Modulo) + if (space == MathSpace::Modulo) { constant = lsum.constant - rsum.constant; - else if (!SafeSub(lsum.constant, rsum.constant, &constant)) + } else if (!SafeSub(lsum.constant, rsum.constant, &constant) || + !MonotoneSub(lsum.constant, rsum.constant)) { return SimpleLinearSum(ins, 0); + } return SimpleLinearSum(lsum.term, constant); } |