[X86] fix combineSubSetcc to handle a large constant (#66941)

llvm · Sep 20, 2023 · 8b04f1e · 8b04f1e
1 parent 2613c77
commit 8b04f1e
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Showing 2 changed files with 22 additions and 1 deletion.
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -54221,7 +54221,7 @@ static SDValue combineSubSetcc(SDNode *N, SelectionDAG &DAG) {
     SDValue SetCC = Op1.getOperand(0);
     X86::CondCode CC = (X86::CondCode)SetCC.getConstantOperandVal(0);
     X86::CondCode NewCC = X86::GetOppositeBranchCondition(CC);
-    uint64_t NewImm = Op0C->getZExtValue() - 1;
+    APInt NewImm = Op0C->getAPIntValue() - 1;
     SDLoc DL(Op1);
     SDValue NewSetCC = getSETCC(NewCC, SetCC.getOperand(1), DL, DAG);
     NewSetCC = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, NewSetCC);

diff --git a/llvm/test/CodeGen/X86/select_const_i128.ll b/llvm/test/CodeGen/X86/select_const_i128.ll
@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 3
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mcpu=x86-64-v2 | FileCheck %s
+
+define i128 @select_eq_i128(ptr %a) {
+; CHECK-LABEL: select_eq_i128:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    movdqa (%rdi), %xmm0
+; CHECK-NEXT:    pxor {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    ptest %xmm0, %xmm0
+; CHECK-NEXT:    setne %al
+; CHECK-NEXT:    xorl %ecx, %ecx
+; CHECK-NEXT:    addq $-1, %rax
+; CHECK-NEXT:    movabsq $9223372036854775807, %rdx # imm = 0x7FFFFFFFFFFFFFFF
+; CHECK-NEXT:    adcq %rcx, %rdx
+; CHECK-NEXT:    retq
+  %1 = load i128, ptr %a, align 16
+  %cmp = icmp eq i128 %1, 1
+  %cond = select i1 %cmp, i128 170141183460469231731687303715884105727, i128 -170141183460469231731687303715884105728
+  ret i128 %cond
+}