[WebAssembly] Teach backend that loadv128 is good under -msimd #149230
Description
In #148298 (comment) (memcmp expand support), in the type legalization stage, type legalization doesn't understand load i128 is load i64x2 etc etc.
Report snippet:
Jasmine: I can add them in but the wasm won't use load128 for now since the type legalization doesn't understand load i128 is load i64x2 etc etc. Should I let this one be in another PR ?
Optimized lowered selection DAG: %bb.0 'memcmp_expand_32:'
SelectionDAG has 21 nodes:
t0: ch,glue = EntryToken
t2: i32 = WebAssemblyISD::ARGUMENT TargetConstant:i32<0>
t4: i32 = WebAssemblyISD::ARGUMENT TargetConstant:i32<1>
t7: i128,ch = load<(load (s128) from %ir.a, align 1)> t0, t2, undef:i32
t8: i128,ch = load<(load (s128) from %ir.b, align 1)> t0, t4, undef:i32
t9: i128 = xor t7, t8
t11: i32 = add t2, Constant:i32<16>
t13: i128,ch = load<(load (s128) from %ir.4, align 1)> t0, t11, undef:i32
t12: i32 = add t4, Constant:i32<16>
t14: i128,ch = load<(load (s128) from %ir.5, align 1)> t0, t12, undef:i32
t15: i128 = xor t13, t14
t16: i128 = or t9, t15
t26: i1 = setcc t16, Constant:i128<0>, seteq:ch
t23: i32 = any_extend t26
t24: ch = WebAssemblyISD::RETURN t0, t23
Type-legalized selection DAG: %bb.0 'memcmp_expand_32:'
SelectionDAG has 33 nodes:
t0: ch,glue = EntryToken
t2: i32 = WebAssemblyISD::ARGUMENT TargetConstant:i32<0>
t4: i32 = WebAssemblyISD::ARGUMENT TargetConstant:i32<1>
t11: i32 = add t2, Constant:i32<16>
t12: i32 = add t4, Constant:i32<16>
t30: i64,ch = load<(load (s64) from %ir.a, align 1)> t0, t2, undef:i32
t35: i64,ch = load<(load (s64) from %ir.b, align 1)> t0, t4, undef:i32
t39: i64 = xor t30, t35
t41: i64,ch = load<(load (s64) from %ir.4, align 1)> t0, t11, undef:i32
t45: i64,ch = load<(load (s64) from %ir.5, align 1)> t0, t12, undef:i32
t49: i64 = xor t41, t45
t51: i64 = or t39, t49
t32: i32 = add nuw t2, Constant:i32<8>
t33: i64,ch = load<(load (s64) from %ir.a + 8, align 1)> t0, t32, undef:i32
t36: i32 = add nuw t4, Constant:i32<8>
t37: i64,ch = load<(load (s64) from %ir.b + 8, align 1)> t0, t36, undef:i32
t40: i64 = xor t33, t37
t42: i32 = add nuw t11, Constant:i32<8>
t43: i64,ch = load<(load (s64) from %ir.4 + 8, align 1)> t0, t42, undef:i32
t46: i32 = add nuw t12, Constant:i32<8>
t47: i64,ch = load<(load (s64) from %ir.5 + 8, align 1)> t0, t46, undef:i32
t50: i64 = xor t43, t47
t52: i64 = or t40, t50
t54: i64 = or t51, t52
t53: i32 = setcc t54, Constant:i64<0>, seteq:ch
t24: ch = WebAssemblyISD::RETURN t0, t53
Luke:Oh in that case yeah I think it's reasonable to start with just scalar sizes now and leave a TODO for vector sizes