diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/passes/OptimizeInstructions.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp index 0ce1f5f95..b11df3276 100644 --- a/src/passes/OptimizeInstructions.cpp +++ b/src/passes/OptimizeInstructions.cpp @@ -346,6 +346,7 @@ struct OptimizeInstructions { // x <<>> (C & (31 | 63)) ==> x <<>> C' // x <<>> (y & (31 | 63)) ==> x <<>> y + // x <<>> (y & (32 | 64)) ==> x // where '<<>>': // '<<', '>>', '>>>'. 'rotl' or 'rotr' BinaryOp op; @@ -375,6 +376,13 @@ struct OptimizeInstructions curr->cast<Binary>()->right = y; return curr; } + // i32(x) <<>> (y & 32) ==> x + // i64(x) <<>> (y & 64) ==> x + if (((c->type == Type::i32 && (c->value.geti32() & 31) == 0) || + (c->type == Type::i64 && (c->value.geti64() & 63LL) == 0LL)) && + !effects(y).hasSideEffects()) { + return x; + } } } { |