================
@@ -20409,6 +20409,9 @@ tryToReplaceScalarFPConversionWithSVE(SDNode *N,
SelectionDAG &DAG,
N->getOpcode() == ISD::FP_TO_UINT_SAT)
return SDValue();
+ if (Subtarget->isStreaming() && Subtarget->hasFPRCVT())
----------------
Lukacma wrote:
As mentioned in previous patch I don't think this is correct guard. Correct me
if I am wrong but here is my reasoning in detail.
Let's take this IR as an example:
```
define i32 @test_fptosi_f16_i32_simd(half %a) {
%r = fptosi half %a to i32
ret i32 %r
}
```
When run with -attr=+sme,+neon,+fullfp16 --force-streaming it lowers to SVE
assembly like this:
```
ptrue p0.s
// kill: def $h0 killed $h0 def $z0
fcvtzs z0.s, p0/m, z0.h
fmov w0, s0
```
Even though it could have compiled to just:
```
fcvtzs w0, h0
```
As is the case in non-streaming mode. Looking at the patch which introduced it,
it seems like it was added to deal with the fact that GPR converts were
incorrectly disabled in streaming mode as I don't see a situation in which
using SVE converts is better than just using the neon ones, when dealing with
fixed length vectors or scalars.
https://github.com/llvm/llvm-project/pull/177334
_______________________________________________
llvm-branch-commits mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
