https://github.com/dyung updated https://github.com/llvm/llvm-project/pull/171596
>From d2e835bd46384aa1628c9d44e3f93438f0795dfd Mon Sep 17 00:00:00 2001 From: Nikita Popov <[email protected]> Date: Wed, 10 Dec 2025 11:31:07 +0100 Subject: [PATCH] [SelectOptimize] Fix incorrect -1 immediate for large integers (#170860) This was creating a -1 with zero extension, while it needs to use sign extension. (cherry picked from commit 1165e41c876f3beba938805329416647bd21ee5e) --- llvm/lib/CodeGen/SelectOptimize.cpp | 2 +- llvm/test/CodeGen/AArch64/selectopt-cast.ll | 46 +++++++++++++++++++++ 2 files changed, 47 insertions(+), 1 deletion(-) diff --git a/llvm/lib/CodeGen/SelectOptimize.cpp b/llvm/lib/CodeGen/SelectOptimize.cpp index 13ed8f28d5507..2052e9a75d89b 100644 --- a/llvm/lib/CodeGen/SelectOptimize.cpp +++ b/llvm/lib/CodeGen/SelectOptimize.cpp @@ -502,7 +502,7 @@ static Value *getTrueOrFalseValue( } else { assert((isa<AShrOperator>(AuxI) || isa<SExtInst>(AuxI)) && "Unexpected opcode"); - CBO->setOperand(CondIdx, ConstantInt::get(CBO->getType(), -1)); + CBO->setOperand(CondIdx, ConstantInt::getAllOnesValue(CBO->getType())); } unsigned OtherIdx = 1 - CondIdx; diff --git a/llvm/test/CodeGen/AArch64/selectopt-cast.ll b/llvm/test/CodeGen/AArch64/selectopt-cast.ll index b862458e99fe2..47cc736ad6880 100644 --- a/llvm/test/CodeGen/AArch64/selectopt-cast.ll +++ b/llvm/test/CodeGen/AArch64/selectopt-cast.ll @@ -901,3 +901,49 @@ loop: exit: ret void } + +define void @sext_i128() { +; CHECK-LABEL: @sext_i128( +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[LOOP:%.*]] +; CHECK: loop: +; CHECK-NEXT: [[I:%.*]] = icmp slt i128 0, 0 +; CHECK-NEXT: [[I2:%.*]] = sext i1 [[I]] to i128 +; CHECK-NEXT: [[I3:%.*]] = or i128 [[I2]], 0 +; CHECK-NEXT: [[I4:%.*]] = icmp slt i128 [[I3]], 0 +; CHECK-NEXT: [[I5:%.*]] = sext i1 [[I4]] to i128 +; CHECK-NEXT: [[I4_FROZEN:%.*]] = freeze i1 [[I4]] +; CHECK-NEXT: br i1 [[I4_FROZEN]], label [[SELECT_TRUE_SINK:%.*]], label [[SELECT_END:%.*]] +; CHECK: select.true.sink: +; CHECK-NEXT: [[TMP0:%.*]] = add i128 -1, 0 +; CHECK-NEXT: br label [[SELECT_END]] +; CHECK: select.end: +; CHECK-NEXT: [[I6:%.*]] = phi i128 [ [[TMP0]], [[SELECT_TRUE_SINK]] ], [ 0, [[LOOP]] ] +; CHECK-NEXT: [[I7:%.*]] = icmp slt i128 [[I6]], 0 +; CHECK-NEXT: [[I8:%.*]] = sext i1 [[I7]] to i128 +; CHECK-NEXT: [[I7_FROZEN:%.*]] = freeze i1 [[I7]] +; CHECK-NEXT: br i1 [[I7_FROZEN]], label [[SELECT_TRUE_SINK2:%.*]], label [[SELECT_END1:%.*]] +; CHECK: select.true.sink2: +; CHECK-NEXT: [[TMP1:%.*]] = add i128 -1, 0 +; CHECK-NEXT: br label [[SELECT_END1]] +; CHECK: select.end1: +; CHECK-NEXT: [[I9:%.*]] = phi i128 [ [[TMP1]], [[SELECT_TRUE_SINK2]] ], [ 0, [[SELECT_END]] ] +; CHECK-NEXT: [[I10:%.*]] = or i128 [[I9]], 0 +; CHECK-NEXT: br label [[LOOP]] +; +entry: + br label %loop + +loop: + %i = icmp slt i128 0, 0 + %i2 = sext i1 %i to i128 + %i3 = or i128 %i2, 0 + %i4 = icmp slt i128 %i3, 0 + %i5 = sext i1 %i4 to i128 + %i6 = add i128 %i5, 0 + %i7 = icmp slt i128 %i6, 0 + %i8 = sext i1 %i7 to i128 + %i9 = add i128 %i8, 0 + %i10 = or i128 %i9, 0 + br label %loop +} _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
