[llvm] [X86] combineAndNotOrIntoAndNotAnd - don't fold other constant operands (PR #113264)

Miguel Saldivar via llvm-commits llvm-commits at lists.llvm.org
Tue Oct 22 10:24:17 PDT 2024


https://github.com/Saldivarcher updated https://github.com/llvm/llvm-project/pull/113264

>From cb1cc3d90a37248bcd7a24c400159b6c32416f1d Mon Sep 17 00:00:00 2001
From: Miguel Saldivar <miguel.saldivar at hpe.com>
Date: Mon, 21 Oct 2024 23:56:09 -0500
Subject: [PATCH] [X86] combineAndNotOrIntoAndNotAnd - don't fold

other constant operands
---
 llvm/lib/Target/X86/X86ISelLowering.cpp |  4 ++--
 llvm/test/CodeGen/X86/pr108731.ll       | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index bcb84add65d83e..c1a381f937acf1 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -50049,8 +50049,8 @@ static SDValue combineAndNotOrIntoAndNotAnd(SDNode *N, SelectionDAG &DAG) {
   SDValue X, Y, Z;
   if (sd_match(N, m_And(m_Value(X),
                         m_OneUse(m_Or(m_Value(Y), m_Not(m_Value(Z))))))) {
-    // Don't fold if Y is a constant to prevent infinite loops.
-    if (!isa<ConstantSDNode>(Y))
+    // Don't fold if Y or Z are constants to prevent infinite loops.
+    if (!isa<ConstantSDNode>(Y) && !isa<ConstantSDNode>(Z))
       return DAG.getNode(
           ISD::AND, DL, VT, X,
           DAG.getNOT(
diff --git a/llvm/test/CodeGen/X86/pr108731.ll b/llvm/test/CodeGen/X86/pr108731.ll
index 473b4f7f4da2e3..2983d108eaeddc 100644
--- a/llvm/test/CodeGen/X86/pr108731.ll
+++ b/llvm/test/CodeGen/X86/pr108731.ll
@@ -192,3 +192,23 @@ define void @PR112347(ptr %p0, ptr %p1, ptr %p2) {
   ret void
 }
 
+define void @PR113240(i64 %a) {
+; CHECK-LABEL: PR113240:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    movq %rdi, %rax
+; CHECK-NEXT:    notq %rax
+; CHECK-NEXT:    movabsq $8796093022206, %rcx # imm = 0x7FFFFFFFFFE
+; CHECK-NEXT:    notq %rcx
+; CHECK-NEXT:    orq %rax, %rcx
+; CHECK-NEXT:    andq %rdi, %rcx
+; CHECK-NEXT:    movq %rcx, 0
+; CHECK-NEXT:    retq
+entry:
+  %and = and i64 %a, 8796093022206
+  %bf.value = and i64 8796093022206, 0
+  %not = xor i64 %and, -1
+  %and4 = and i64 %a, %not
+  store i64 %and4, ptr null, align 8
+  ret void
+}
+



More information about the llvm-commits mailing list