diff options
| -rw-r--r-- | src/passes/OptimizeInstructions.cpp | 6 | ||||
| -rw-r--r-- | test/passes/optimize-instructions.txt | 59 | ||||
| -rw-r--r-- | test/passes/optimize-instructions.wast | 82 |
3 files changed, 147 insertions, 0 deletions
diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp index 1c549cab6..cf5ad982e 100644 --- a/src/passes/OptimizeInstructions.cpp +++ b/src/passes/OptimizeInstructions.cpp @@ -525,6 +525,12 @@ struct OptimizeInstructions : public WalkerPass<PostWalker<OptimizeInstructions, } } } + } else if (auto* ext = getSignExt(binary)) { + // if sign extending the exact bit size we store, we can skip the extension + // if extending something bigger, then we just alter bits we don't save anyhow + if (getSignExtBits(binary) >= store->bytes * 8) { + store->value = ext; + } } } else if (auto* unary = store->value->dynCast<Unary>()) { if (unary->op == WrapInt64) { diff --git a/test/passes/optimize-instructions.txt b/test/passes/optimize-instructions.txt index 7daf6815c..d36f1ffad 100644 --- a/test/passes/optimize-instructions.txt +++ b/test/passes/optimize-instructions.txt @@ -4,6 +4,7 @@ (type $2 (func (result i32))) (type $3 (func (param i32) (result i32))) (type $4 (func (param i32 i32))) + (type $5 (func (param i32))) (memory $0 0) (export "load-off-2" (func $load-off-2)) (func $f (type $0) (param $i1 i32) (param $i2 i64) @@ -1141,4 +1142,62 @@ (get_local $0) ) ) + (func $store-signext (type $5) (param $0 i32) + (i32.store8 + (i32.const 8) + (get_local $0) + ) + (i32.store8 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 25) + ) + (i32.const 25) + ) + ) + (i32.store8 + (i32.const 8) + (get_local $0) + ) + (i32.store16 + (i32.const 8) + (get_local $0) + ) + (i32.store16 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 17) + ) + (i32.const 17) + ) + ) + (i32.store16 + (i32.const 8) + (get_local $0) + ) + (i32.store + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 16) + ) + (i32.const 16) + ) + ) + (i32.store + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 8) + ) + (i32.const 8) + ) + ) + ) ) diff --git a/test/passes/optimize-instructions.wast b/test/passes/optimize-instructions.wast index 9bd5d975a..6cba3d51f 100644 --- a/test/passes/optimize-instructions.wast +++ b/test/passes/optimize-instructions.wast @@ -1419,4 +1419,86 @@ ) ) ) + (func $store-signext (param $0 i32) + (i32.store8 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 24) ;; exact size we store, sign-ext of 8 bits + ) + (i32.const 24) + ) + ) + (i32.store8 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 25) ;; 7 bits. so the ext can alter a bit we store, do not optimize + ) + (i32.const 25) + ) + ) + (i32.store8 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 23) ;; 9 bits, this is good to optimize + ) + (i32.const 23) + ) + ) + (i32.store16 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 16) ;; exact size we store, sign-ext of 16 bits + ) + (i32.const 16) + ) + ) + (i32.store16 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 17) ;; 15 bits. so the ext can alter a bit we store, do not optimize + ) + (i32.const 17) + ) + ) + (i32.store16 + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 14) ;; 17 bits, this is good to optimize + ) + (i32.const 14) + ) + ) + (i32.store + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 16) ;; 4 bytes stored, do nothing + ) + (i32.const 16) + ) + ) + (i32.store + (i32.const 8) + (i32.shr_s + (i32.shl + (get_local $0) + (i32.const 8) ;; 4 bytes stored, do nothing + ) + (i32.const 8) + ) + ) + ) ) |