[llvm] 5a457bd - Revert rGa5f637bcbb7d1e08ce637f113fc117c3f4b2b110 "[X86] Fold AND(SRL(X,Y),1) -> SETCC(BT(X,Y))"

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2022-04-01T16:48:24+01:00
New Revision: 5a457bd2fa5ca2f7ec2be356bfd3a8f084139886

URL: https://github.com/llvm/llvm-project/commit/5a457bd2fa5ca2f7ec2be356bfd3a8f084139886
DIFF: https://github.com/llvm/llvm-project/commit/5a457bd2fa5ca2f7ec2be356bfd3a8f084139886.diff

LOG: Revert rGa5f637bcbb7d1e08ce637f113fc117c3f4b2b110 "[X86] Fold AND(SRL(X,Y),1) -> SETCC(BT(X,Y))"

Investigating a sanitizer-windows buildbot breakage

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp
    llvm/test/CodeGen/X86/setcc.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 4fe1d72127927..f78a010ea40b4 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -47329,19 +47329,6 @@ static SDValue combineAnd(SDNode *N, SelectionDAG &DAG,
   if (SDValue R = combineAndLoadToBZHI(N, DAG, Subtarget))
     return R;
 
-  // Fold AND(SRL(X,Y),1) -> SETCC(BT(X,Y), COND_B) iff Y is not a constant
-  // avoids slow variable shift (moving shift amount to ECX etc.)
-  if (isOneConstant(N1) && N0->hasOneUse()) {
-    SDValue Src = N0;
-    while ((Src.getOpcode() == ISD::ZERO_EXTEND ||
-            Src.getOpcode() == ISD::TRUNCATE) &&
-           Src.getOperand(0)->hasOneUse())
-      Src = Src.getOperand(0);
-    if (Src.getOpcode() == ISD::SRL && !isa<ConstantSDNode>(Src.getOperand(1)))
-      if (SDValue BT = getBT(Src.getOperand(0), Src.getOperand(1), dl, DAG))
-        return getSETCC(X86::COND_B, BT, dl, DAG);
-  }
-
   if (VT.isVector() && (VT.getScalarSizeInBits() % 8) == 0) {
     // Attempt to recursively combine a bitmask AND with shuffles.
     SDValue Op(N, 0);

diff  --git a/llvm/test/CodeGen/X86/setcc.ll b/llvm/test/CodeGen/X86/setcc.ll
index 229632b25dcf5..57431887f58c6 100644
--- a/llvm/test/CodeGen/X86/setcc.ll
+++ b/llvm/test/CodeGen/X86/setcc.ll
@@ -139,17 +139,19 @@ define zeroext i1 @t6(i32 %a) #0 {
 define zeroext i1 @t7(i32 %0) {
 ; X86-LABEL: t7:
 ; X86:       ## %bb.0:
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movl $19, %ecx
-; X86-NEXT:    btl %eax, %ecx
-; X86-NEXT:    setb %al
+; X86-NEXT:    movb {{[0-9]+}}(%esp), %cl
+; X86-NEXT:    movb $19, %al
+; X86-NEXT:    shrb %cl, %al
+; X86-NEXT:    andb $1, %al
 ; X86-NEXT:    retl
 ;
 ; X64-LABEL: t7:
 ; X64:       ## %bb.0:
-; X64-NEXT:    movl $19, %eax
-; X64-NEXT:    btl %edi, %eax
-; X64-NEXT:    setb %al
+; X64-NEXT:    movl %edi, %ecx
+; X64-NEXT:    movb $19, %al
+; X64-NEXT:    ## kill: def $cl killed $cl killed $ecx
+; X64-NEXT:    shrb %cl, %al
+; X64-NEXT:    andb $1, %al
 ; X64-NEXT:    retq
   %2 = trunc i32 %0 to i5
   %3 = lshr i5 -13, %2
@@ -161,16 +163,20 @@ define zeroext i1 @t7(i32 %0) {
 define zeroext i1 @t8(i8 %0, i8 %1) {
 ; X86-LABEL: t8:
 ; X86:       ## %bb.0:
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
-; X86-NEXT:    btl %eax, %ecx
-; X86-NEXT:    setb %al
+; X86-NEXT:    movb {{[0-9]+}}(%esp), %cl
+; X86-NEXT:    movb {{[0-9]+}}(%esp), %al
+; X86-NEXT:    shrb %cl, %al
+; X86-NEXT:    andb $1, %al
 ; X86-NEXT:    retl
 ;
 ; X64-LABEL: t8:
 ; X64:       ## %bb.0:
-; X64-NEXT:    btl %esi, %edi
-; X64-NEXT:    setb %al
+; X64-NEXT:    movl %esi, %ecx
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    ## kill: def $cl killed $cl killed $ecx
+; X64-NEXT:    shrb %cl, %al
+; X64-NEXT:    andb $1, %al
+; X64-NEXT:    ## kill: def $al killed $al killed $eax
 ; X64-NEXT:    retq
   %3 = lshr i8 %0, %1
   %4 = and i8 %3, 1