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[OptimizeForJS] Avoid 64-bit integer storage if it's possible #4083

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[OptimizeForJS] Avoid 64-bit integer storage if it's possible #4083

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fa56857
init
MaxGraey Aug 14, 2021
6133f1d
more tests
MaxGraey Aug 14, 2021
b026eba
fix
MaxGraey Aug 16, 2021
f628ede
add test
MaxGraey Aug 16, 2021
b1eafba
skip subnormals as well
MaxGraey Aug 16, 2021
0cc0da3
update lit tests
MaxGraey Aug 16, 2021
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19 changes: 19 additions & 0 deletions src/passes/OptimizeForJS.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,25 @@ struct OptimizeForJSPass : public WalkerPass<PostWalker<OptimizeForJSPass>> {
builder.makeLocalGet(temp.index, type),
builder.makeConst(Literal::makeOne(type.getBasic())))))));
}

void visitStore(Store* curr) {
// i64.store(x, C) ==> f64.store(x, C'),
// where C' <- reinterpret<f64>(C)
// and C' != NaN && !is_subnormal(C')
//
// Regarding 0x8000000000000000. Closure Compiler preserve -0.0
// so it should be safe but make sure your minifactor does not
// turn -0.0 into +0.0.
if (curr->valueType == Type::i64 && curr->bytes == 8) {
if (auto* c = curr->value->dynCast<Const>()) {
double value = c->value.reinterpretf64();
if (!std::isnan(value) && std::fpclassify(value) != FP_SUBNORMAL) {
curr->valueType = Type::f64;
c->set(Literal(value));
}
}
}
}
};

Pass* createOptimizeForJSPass() { return new OptimizeForJSPass(); }
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98 changes: 98 additions & 0 deletions test/lit/passes/optimize-for-js.wast
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Expand Up @@ -3,6 +3,11 @@
;; RUN: | filecheck %s

(module
(memory 0)

;; i32.popcnt(x) == 1,
;; i64.popcnt(x) == 1 => !!x & !(x & (x - 1))

;; CHECK: (func $is-power-of-2_32 (param $x i32) (result i32)
;; CHECK-NEXT: (i32.and
;; CHECK-NEXT: (i32.eqz
Expand Down Expand Up @@ -80,4 +85,97 @@
(i64.const 1)
)
)

;; i64.store(ptr, C) => f64.store(ptr, reinterpret<f64>(C))

;; CHECK: (func $store-const-zero (param $ptr i32)
;; CHECK-NEXT: (f64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (f64.const 0)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-const-zero (param $ptr i32)
(i64.store (local.get $ptr) (i64.const 0))
)
;; CHECK: (func $store-const-smin (param $ptr i32)
;; CHECK-NEXT: (f64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (f64.const -0)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-const-smin (param $ptr i32)
(i64.store (local.get $ptr) (i64.const 0x8000000000000000))
)
;; CHECK: (func $store-const-minus-inf (param $ptr i32)
;; CHECK-NEXT: (f64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (f64.const -inf)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-const-minus-inf (param $ptr i32)
(i64.store (local.get $ptr) (i64.const 0xFFF0000000000000))
)
;; CHECK: (func $store-const-one_subnorm_skip (param $ptr i32)
;; CHECK-NEXT: (i64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (i64.const 1)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-const-one_subnorm_skip (param $ptr i32)
(i64.store (local.get $ptr) (i64.const 1))
)
;; CHECK: (func $store-const-two_subnorm_skip (param $ptr i32)
;; CHECK-NEXT: (i64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (i64.const 2)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-const-two_subnorm_skip (param $ptr i32)
(i64.store (local.get $ptr) (i64.const 2))
)
;; CHECK: (func $store-unsafe-const-1_skip (param $ptr i32)
;; CHECK-NEXT: (i64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (i64.const -1)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-unsafe-const-1_skip (param $ptr i32)
(i64.store (local.get $ptr) (i64.const -1)) ;; will be NaN
)
;; CHECK: (func $store-unsafe-const-2_skip (param $ptr i32)
;; CHECK-NEXT: (i64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (i64.const -2)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-unsafe-const-2_skip (param $ptr i32)
(i64.store (local.get $ptr) (i64.const -2))
)
;; CHECK: (func $store-unsafe-const-3_skip (param $ptr i32)
;; CHECK-NEXT: (i64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (i64.const -2251799813685248)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-unsafe-const-3_skip (param $ptr i32)
(i64.store (local.get $ptr) (i64.const 0xFFF8000000000000))
)
;; CHECK: (func $store-non-const_skip (param $ptr i32) (param $x i64)
;; CHECK-NEXT: (i64.store
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (local.get $x)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-non-const_skip (param $ptr i32) (param $x i64)
(i64.store (local.get $ptr) (local.get $x))
)
;; CHECK: (func $store-non-8-bytes_skip (param $ptr i32)
;; CHECK-NEXT: (i64.store32
;; CHECK-NEXT: (local.get $ptr)
;; CHECK-NEXT: (i64.const 2)
;; CHECK-NEXT: )
;; CHECK-NEXT: )
(func $store-non-8-bytes_skip (param $ptr i32)
(i64.store32 (local.get $ptr) (i64.const 2))
)
)
13 changes: 1 addition & 12 deletions test/wasm2js/unaligned.2asm.js.opt
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Expand Up @@ -76,17 +76,6 @@ function asmFunc(env) {
}

function $5() {
HEAP8[0] = 0;
HEAP8[1] = 0;
HEAP8[2] = 0;
HEAP8[3] = 0;
HEAP8[4] = 0;
HEAP8[5] = 0;
HEAP8[6] = 0;
HEAP8[7] = 0;
}

function $7() {
var $0_1 = 0, $1 = 0;
wasm2js_scratch_store_f64(0.0);
$0_1 = wasm2js_scratch_load_i32(1) | 0;
Expand Down Expand Up @@ -122,7 +111,7 @@ function asmFunc(env) {
"i32_store": $4,
"i64_store": $5,
"f32_store": $4,
"f64_store": $7
"f64_store": $5
};
}

Expand Down