[llvm] 846712b - [DAG] combineSelect - select(i1,vXi1,vXi1) - only cast <X x i1> constants to iX pre-legalization or if its a legal type

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2023-04-06T13:35:45+01:00
New Revision: 846712b0cb133f0ebfaf5be41818183b4c86f0a1

URL: https://github.com/llvm/llvm-project/commit/846712b0cb133f0ebfaf5be41818183b4c86f0a1
DIFF: https://github.com/llvm/llvm-project/commit/846712b0cb133f0ebfaf5be41818183b4c86f0a1.diff

LOG: [DAG] combineSelect - select(i1,vXi1,vXi1) - only cast <X x i1> constants to iX pre-legalization or if its a legal type

Fixes #61524

Added: 
    llvm/test/CodeGen/X86/pr61524.ll

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index dc07a034b189..88495d8f7fbe 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -46812,27 +46812,27 @@ static SDValue combineSelect(SDNode *N, SelectionDAG &DAG,
       VT.getVectorElementType() == MVT::i1 &&
       (DCI.isBeforeLegalize() || (VT != MVT::v64i1 || Subtarget.is64Bit()))) {
     EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), VT.getVectorNumElements());
-    bool LHSIsConst = ISD::isBuildVectorOfConstantSDNodes(LHS.getNode());
-    bool RHSIsConst = ISD::isBuildVectorOfConstantSDNodes(RHS.getNode());
-
-    if ((LHSIsConst ||
-         (LHS.getOpcode() == ISD::BITCAST &&
-          LHS.getOperand(0).getValueType() == IntVT)) &&
-        (RHSIsConst ||
-         (RHS.getOpcode() == ISD::BITCAST &&
-          RHS.getOperand(0).getValueType() == IntVT))) {
-      if (LHSIsConst)
-        LHS = combinevXi1ConstantToInteger(LHS, DAG);
-      else
-        LHS = LHS.getOperand(0);
+    if (DCI.isBeforeLegalize() || TLI.isTypeLegal(IntVT)) {
+      bool LHSIsConst = ISD::isBuildVectorOfConstantSDNodes(LHS.getNode());
+      bool RHSIsConst = ISD::isBuildVectorOfConstantSDNodes(RHS.getNode());
+
+      if ((LHSIsConst || (LHS.getOpcode() == ISD::BITCAST &&
+                          LHS.getOperand(0).getValueType() == IntVT)) &&
+          (RHSIsConst || (RHS.getOpcode() == ISD::BITCAST &&
+                          RHS.getOperand(0).getValueType() == IntVT))) {
+        if (LHSIsConst)
+          LHS = combinevXi1ConstantToInteger(LHS, DAG);
+        else
+          LHS = LHS.getOperand(0);
 
-      if (RHSIsConst)
-        RHS = combinevXi1ConstantToInteger(RHS, DAG);
-      else
-        RHS = RHS.getOperand(0);
+        if (RHSIsConst)
+          RHS = combinevXi1ConstantToInteger(RHS, DAG);
+        else
+          RHS = RHS.getOperand(0);
 
-      SDValue Select = DAG.getSelect(DL, IntVT, Cond, LHS, RHS);
-      return DAG.getBitcast(VT, Select);
+        SDValue Select = DAG.getSelect(DL, IntVT, Cond, LHS, RHS);
+        return DAG.getBitcast(VT, Select);
+      }
     }
   }
 

diff  --git a/llvm/test/CodeGen/X86/pr61524.ll b/llvm/test/CodeGen/X86/pr61524.ll
new file mode 100644
index 000000000000..0f4ccd6498fe
--- /dev/null
+++ b/llvm/test/CodeGen/X86/pr61524.ll
@@ -0,0 +1,26 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s --mtriple=x86_64-- -mcpu=cascadelake | FileCheck %s
+
+define <3 x i1> @repro(i1 %cond) {
+; CHECK-LABEL: repro:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    testb $1, %dil
+; CHECK-NEXT:    jne .LBB0_1
+; CHECK-NEXT:  # %bb.2:
+; CHECK-NEXT:    kxorw %k0, %k0, %k0
+; CHECK-NEXT:    jmp .LBB0_3
+; CHECK-NEXT:  .LBB0_1:
+; CHECK-NEXT:    kxnorw %k0, %k0, %k0
+; CHECK-NEXT:  .LBB0_3:
+; CHECK-NEXT:    kshiftrb $1, %k0, %k1
+; CHECK-NEXT:    kmovd %k1, %edx
+; CHECK-NEXT:    kshiftrb $2, %k0, %k1
+; CHECK-NEXT:    kmovd %k1, %ecx
+; CHECK-NEXT:    kmovd %k0, %eax
+; CHECK-NEXT:    # kill: def $al killed $al killed $eax
+; CHECK-NEXT:    # kill: def $dl killed $dl killed $edx
+; CHECK-NEXT:    # kill: def $cl killed $cl killed $ecx
+; CHECK-NEXT:    retq
+  %select = select i1 %cond, <3 x i1> <i1 true, i1 true, i1 true>, <3 x i1> zeroinitializer
+  ret <3 x i1> %select
+}