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Diffstat (limited to 'src/passes/OptimizeInstructions.cpp')
| -rw-r--r-- | src/passes/OptimizeInstructions.cpp | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp index c4a5b2ed4..c4ce8c239 100644 --- a/src/passes/OptimizeInstructions.cpp +++ b/src/passes/OptimizeInstructions.cpp @@ -476,6 +476,22 @@ struct OptimizeInstructions break; } } + // i32(x) << 24 >> 24 ==> i32.extend8_s(x) + // i32(x) << 16 >> 16 ==> i32.extend16_s(x) + if (matches(curr, + binary(ShrSInt32, + binary(ShlInt32, any(&x), i32(&c1)), + i32(&c2))) && + Bits::getEffectiveShifts(c1) == Bits::getEffectiveShifts(c2)) { + switch (32 - Bits::getEffectiveShifts(c1)) { + case 8: + return replaceCurrent(builder.makeUnary(ExtendS8Int32, x)); + case 16: + return replaceCurrent(builder.makeUnary(ExtendS16Int32, x)); + default: + break; + } + } } } { |