[llvm] 1234754 - [DAGCombine] `BUILD_VECTOR` can not create undef or poison

[Roman Lebedev via llvm-commits]

Author: Roman Lebedev
Date: 2022-12-23T02:26:36+03:00
New Revision: 1234754bbca77c74d78d2200a42dcdf55804856f

URL: https://github.com/llvm/llvm-project/commit/1234754bbca77c74d78d2200a42dcdf55804856f
DIFF: https://github.com/llvm/llvm-project/commit/1234754bbca77c74d78d2200a42dcdf55804856f.diff

LOG: [DAGCombine] `BUILD_VECTOR` can not create undef or poison

Added: 
    

Modified: 
    llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    llvm/test/CodeGen/X86/freeze-vector.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index a39d0a50bd87..928e61d5ceea 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -4736,6 +4736,7 @@ bool SelectionDAG::canCreateUndefOrPoison(SDValue Op, const APInt &DemandedElts,
   case ISD::SIGN_EXTEND_VECTOR_INREG:
   case ISD::ZERO_EXTEND_VECTOR_INREG:
   case ISD::BITCAST:
+  case ISD::BUILD_VECTOR:
     return false;
 
   case ISD::ADD:

diff  --git a/llvm/test/CodeGen/X86/freeze-vector.ll b/llvm/test/CodeGen/X86/freeze-vector.ll
index d6eb0f9308db..4604416e98e4 100644
--- a/llvm/test/CodeGen/X86/freeze-vector.ll
+++ b/llvm/test/CodeGen/X86/freeze-vector.ll
@@ -268,20 +268,16 @@ define void @freeze_buildvector_single_maybe_poison_operand(ptr %origin, ptr %ds
 ; X86:       # %bb.0:
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
 ; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
-; X86-NEXT:    movl (%ecx), %ecx
-; X86-NEXT:    andl $15, %ecx
 ; X86-NEXT:    vmovdqa {{.*#+}} xmm0 = <u,42,42,42>
-; X86-NEXT:    vpinsrd $0, %ecx, %xmm0, %xmm0
+; X86-NEXT:    vpinsrd $0, (%ecx), %xmm0, %xmm0
 ; X86-NEXT:    vpand {{\.?LCPI[0-9]+_[0-9]+}}, %xmm0, %xmm0
 ; X86-NEXT:    vmovdqa %xmm0, (%eax)
 ; X86-NEXT:    retl
 ;
 ; X64-LABEL: freeze_buildvector_single_maybe_poison_operand:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl (%rdi), %eax
-; X64-NEXT:    andl $15, %eax
 ; X64-NEXT:    vmovdqa {{.*#+}} xmm0 = <u,42,42,42>
-; X64-NEXT:    vpinsrd $0, %eax, %xmm0, %xmm0
+; X64-NEXT:    vpinsrd $0, (%rdi), %xmm0, %xmm0
 ; X64-NEXT:    vpbroadcastd {{.*#+}} xmm1 = [7,7,7,7]
 ; X64-NEXT:    vpand %xmm1, %xmm0, %xmm0
 ; X64-NEXT:    vmovdqa %xmm0, (%rsi)
@@ -314,10 +310,8 @@ define void @freeze_buildvector_single_repeated_maybe_poison_operand(ptr %origin
 ;
 ; X64-LABEL: freeze_buildvector_single_repeated_maybe_poison_operand:
 ; X64:       # %bb.0:
-; X64-NEXT:    movl (%rdi), %eax
-; X64-NEXT:    andl $15, %eax
 ; X64-NEXT:    vmovdqa {{.*#+}} xmm0 = <u,42,u,u>
-; X64-NEXT:    vpinsrd $0, %eax, %xmm0, %xmm0
+; X64-NEXT:    vpinsrd $0, (%rdi), %xmm0, %xmm0
 ; X64-NEXT:    vpbroadcastq %xmm0, %xmm0
 ; X64-NEXT:    vpbroadcastd {{.*#+}} xmm1 = [7,7,7,7]
 ; X64-NEXT:    vpand %xmm1, %xmm0, %xmm0