[PATCH] D77152: [SelectionDAG] Better legalization for FSHL and FSHR

[Jay Foad via Phabricator via llvm-commits]

foad marked an inline comment as done.
foad added inline comments.


================
Comment at: llvm/test/CodeGen/X86/vector-fshl-rot-128.ll:1670-1675
 ; X32-SSE-NEXT:    movdqa %xmm0, %xmm1
 ; X32-SSE-NEXT:    psrlq $50, %xmm1
+; X32-SSE-NEXT:    movsd {{.*#+}} xmm1 = xmm1[0,1]
 ; X32-SSE-NEXT:    psllq $14, %xmm0
-; X32-SSE-NEXT:    por %xmm1, %xmm0
+; X32-SSE-NEXT:    movsd {{.*#+}} xmm0 = xmm0[0,1]
+; X32-SSE-NEXT:    orpd %xmm1, %xmm0
----------------
Can anyone suggest what might have caused this regression? We get two presumably redundant movsd instructions:
```
	psrlq	$50, %xmm1
	movsd	%xmm1, %xmm1            # xmm1 = xmm1[0,1]
	psllq	$14, %xmm0
	movsd	%xmm0, %xmm0            # xmm0 = xmm0[0,1]
	orpd	%xmm1, %xmm0
```


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D77152/new/

https://reviews.llvm.org/D77152