[llvm] 953013a - [AArch64][GlobalISel] Prevented llvm.aarch64.sisd.fcvtxn fallback (#159811)

[via llvm-commits]

Author: Joshua Rodriguez
Date: 2025-09-22T10:31:27+01:00
New Revision: 953013a91999657683c945a7c586c8eeea05b836

URL: https://github.com/llvm/llvm-project/commit/953013a91999657683c945a7c586c8eeea05b836
DIFF: https://github.com/llvm/llvm-project/commit/953013a91999657683c945a7c586c8eeea05b836.diff

LOG: [AArch64][GlobalISel] Prevented llvm.aarch64.sisd.fcvtxn fallback (#159811)

Added extra check in AArch64RegisterBankInfo.cpp to mark
llvm.aarch64.sisd.fcvtxn as having floating point operands

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp
    llvm/test/CodeGen/AArch64/arm64-vcvtxd_f32_f64.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp
index 62de86bf87f55..eeb34e12993b9 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64RegisterBankInfo.cpp
@@ -486,6 +486,7 @@ static bool isFPIntrinsic(const MachineRegisterInfo &MRI,
   case Intrinsic::aarch64_crypto_sha1c:
   case Intrinsic::aarch64_crypto_sha1p:
   case Intrinsic::aarch64_crypto_sha1m:
+  case Intrinsic::aarch64_sisd_fcvtxn:
     return true;
   case Intrinsic::aarch64_neon_saddlv: {
     const LLT SrcTy = MRI.getType(MI.getOperand(2).getReg());

diff  --git a/llvm/test/CodeGen/AArch64/arm64-vcvtxd_f32_f64.ll b/llvm/test/CodeGen/AArch64/arm64-vcvtxd_f32_f64.ll
index 5dd882106883d..284d36bdfe232 100644
--- a/llvm/test/CodeGen/AArch64/arm64-vcvtxd_f32_f64.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-vcvtxd_f32_f64.ll
@@ -1,8 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
 ; RUN: llc < %s -mtriple=arm64-eabi | FileCheck %s
-; RUN: llc < %s -mtriple=arm64-eabi -global-isel -global-isel-abort=2 2>&1 | FileCheck %s --check-prefixes=CHECK,CHECK-GI
-
-; CHECK-GI:       warning: Instruction selection used fallback path for fcvtxn
+; RUN: llc < %s -mtriple=arm64-eabi -global-isel | FileCheck %s --check-prefixes=CHECK
 
 define float @fcvtxn(double %a) {
 ; CHECK-LABEL: fcvtxn: