https://github.com/tru updated https://github.com/llvm/llvm-project/pull/150902
>From c52ff1a82579c0730151aca412449ea75ae12d03 Mon Sep 17 00:00:00 2001 From: Nikita Popov <npo...@redhat.com> Date: Mon, 28 Jul 2025 10:36:40 +0200 Subject: [PATCH] Revert "[MIPS]Fix QNaNs in the MIPS legacy NaN encodings" (#150773) Reverts llvm/llvm-project#139829. We can't just randomly change the value of constants during lowering. Fixes https://github.com/llvm/llvm-project/issues/149295. (cherry picked from commit 525090e83ca392753d371602b5e64f06e7debd9a) --- llvm/lib/Target/Mips/MipsISelLowering.cpp | 29 ----------------------- llvm/lib/Target/Mips/MipsISelLowering.h | 1 - llvm/test/CodeGen/Mips/nan_lowering.ll | 25 +++++++++++++++++++ llvm/test/CodeGen/Mips/qnan.ll | 14 ----------- 4 files changed, 25 insertions(+), 44 deletions(-) create mode 100644 llvm/test/CodeGen/Mips/nan_lowering.ll delete mode 100644 llvm/test/CodeGen/Mips/qnan.ll diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp index 0e581a7a16503..ec6b382151660 100644 --- a/llvm/lib/Target/Mips/MipsISelLowering.cpp +++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp @@ -522,9 +522,6 @@ MipsTargetLowering::MipsTargetLowering(const MipsTargetMachine &TM, setOperationAction(ISD::TRAP, MVT::Other, Legal); - setOperationAction(ISD::ConstantFP, MVT::f32, Custom); - setOperationAction(ISD::ConstantFP, MVT::f64, Custom); - setTargetDAGCombine({ISD::SDIVREM, ISD::UDIVREM, ISD::SELECT, ISD::AND, ISD::OR, ISD::ADD, ISD::SUB, ISD::AssertZext, ISD::SHL, ISD::SIGN_EXTEND}); @@ -1360,8 +1357,6 @@ LowerOperation(SDValue Op, SelectionDAG &DAG) const case ISD::FP_TO_SINT: return lowerFP_TO_SINT(Op, DAG); case ISD::READCYCLECOUNTER: return lowerREADCYCLECOUNTER(Op, DAG); - case ISD::ConstantFP: - return lowerConstantFP(Op, DAG); } return SDValue(); } @@ -3019,30 +3014,6 @@ SDValue MipsTargetLowering::lowerFP_TO_SINT(SDValue Op, return DAG.getNode(ISD::BITCAST, SDLoc(Op), Op.getValueType(), Trunc); } -SDValue MipsTargetLowering::lowerConstantFP(SDValue Op, - SelectionDAG &DAG) const { - SDLoc DL(Op); - EVT VT = Op.getSimpleValueType(); - SDNode *N = Op.getNode(); - ConstantFPSDNode *CFP = cast<ConstantFPSDNode>(N); - - if (!CFP->isNaN() || Subtarget.isNaN2008()) { - return SDValue(); - } - - APFloat NaNValue = CFP->getValueAPF(); - auto &Sem = NaNValue.getSemantics(); - - // The MSB of the mantissa should be zero for QNaNs in the MIPS legacy NaN - // encodings, and one for sNaNs. Check every NaN constants and make sure - // they are correctly encoded for legacy encodings. - if (!NaNValue.isSignaling()) { - APFloat RealQNaN = NaNValue.getSNaN(Sem); - return DAG.getConstantFP(RealQNaN, DL, VT); - } - return SDValue(); -} - //===----------------------------------------------------------------------===// // Calling Convention Implementation //===----------------------------------------------------------------------===// diff --git a/llvm/lib/Target/Mips/MipsISelLowering.h b/llvm/lib/Target/Mips/MipsISelLowering.h index 31ac5d4c185bc..c65c76ccffc75 100644 --- a/llvm/lib/Target/Mips/MipsISelLowering.h +++ b/llvm/lib/Target/Mips/MipsISelLowering.h @@ -592,7 +592,6 @@ class TargetRegisterClass; SDValue lowerEH_DWARF_CFA(SDValue Op, SelectionDAG &DAG) const; SDValue lowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const; SDValue lowerREADCYCLECOUNTER(SDValue Op, SelectionDAG &DAG) const; - SDValue lowerConstantFP(SDValue Op, SelectionDAG &DAG) const; /// isEligibleForTailCallOptimization - Check whether the call is eligible /// for tail call optimization. diff --git a/llvm/test/CodeGen/Mips/nan_lowering.ll b/llvm/test/CodeGen/Mips/nan_lowering.ll new file mode 100644 index 0000000000000..2a11278e14b6c --- /dev/null +++ b/llvm/test/CodeGen/Mips/nan_lowering.ll @@ -0,0 +1,25 @@ +; RUN: llc -mtriple=mips-linux-gnu -mattr=-nan2008 < %s | FileCheck %s +; RUN: llc -mtriple=mips-linux-gnu -mattr=+nan2008 < %s | FileCheck %s + +; Make sure that lowering does not corrupt the value of NaN values, +; regardless of what the NaN mode is. + +define float @test1() { +; CHECK: .4byte 0x7fc00000 + ret float bitcast (i32 u0x7fc00000 to float) +} + +define float @test2() { +; CHECK: .4byte 0x7fc00001 + ret float bitcast (i32 u0x7fc00001 to float) +} + +define float @test3() { +; CHECK: .4byte 0x7f800000 + ret float bitcast (i32 u0x7f800000 to float) +} + +define float @test4() { +; CHECK: .4byte 0x7f800001 + ret float bitcast (i32 u0x7f800001 to float) +} diff --git a/llvm/test/CodeGen/Mips/qnan.ll b/llvm/test/CodeGen/Mips/qnan.ll deleted file mode 100644 index e5b4aa1b42ee7..0000000000000 --- a/llvm/test/CodeGen/Mips/qnan.ll +++ /dev/null @@ -1,14 +0,0 @@ -; RUN: llc -O3 -mcpu=mips32r2 -mtriple=mips-linux-gnu < %s -o - | FileCheck %s -check-prefixes=MIPS_Legacy -; RUN: llc -O3 -mcpu=mips32r2 -mtriple=mips-linux-gnu -mattr=+nan2008 < %s -o - | FileCheck %s -check-prefixes=MIPS_NaN2008 - -define dso_local float @nan(float noundef %a, float noundef %b) local_unnamed_addr #0 { -; MIPS_Legacy: $CPI0_0: -; MIPS_Legacy-NEXT: .4byte 0x7fa00000 # float NaN - -; MIPS_NaN2008: $CPI0_0: -; MIPS_NaN2008-NEXT: .4byte 0x7fc00000 # float NaN - -entry: - %0 = tail call float @llvm.minimum.f32(float %a, float %b) - ret float %0 -} _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
