[Optimize Instructions] Combine reinterprets, loads and stores (#4006)

Fixes #3973

Loads:

f32.reinterpret_i32(i32.load(x))  =>  f32.load(x)
f64.reinterpret_i64(i64.load(x))  =>  f64.load(x)
i32.reinterpret_f32(f32.load(x))  =>  i32.load(x)
i64.reinterpret_f64(f64.load(x))  =>  i64.load(x)

Stores:

f32.store(y, f32.reinterpret_i32(x))  =>  i32.store(y, x)
f64.store(y, f64.reinterpret_i64(x))  =>  i64.store(y, x)
i32.store(y, i32.reinterpret_f32(x))  =>  f32.store(y, x)
i64.store(y, i64.reinterpret_f64(x))  =>  f64.store(y, x)

Also optimize reinterprets that are undone:

i32.reinterpret_f32(f32.reinterpret_i32(x))  =>  x
i64.reinterpret_f64(f64.reinterpret_i64(x))  =>  x
f32.reinterpret_i32(i32.reinterpret_f32(x))  =>  x
f64.reinterpret_i64(i64.reinterpret_f64(x))  =>  x

1 files changed, 5 insertions, 0 deletions

diff --git a/src/ir/abstract.h b/src/ir/abstract.h
index e5dfd57e0..2308c47ba 100644
--- a/src/ir/abstract.h
+++ b/src/ir/abstract.h
@@ -67,6 +67,11 @@ inline bool hasAnyShift(BinaryOp op) {
          op == RotRInt64;
 }
 
+inline bool hasAnyReinterpret(UnaryOp op) {
+  return op == ReinterpretInt32 || op == ReinterpretInt64 ||
+         op == ReinterpretFloat32 || op == ReinterpretFloat64;
+}
+
 // Provide a wasm type and an abstract op and get the concrete one. For example,
 // you can provide i32 and Add and receive the specific opcode for a 32-bit
 // addition, AddInt32. If the op does not exist, it returns Invalid.