[llvm] 17e293d - [LLVM][AArch64]CFINV - Add UNPREDICTABLE behaviour if CRm is not zero (#140593)

[via llvm-commits]

Author: CarolineConcatto
Date: 2025-05-20T17:11:11+01:00
New Revision: 17e293d5b8f1e4486606127f2bc2fa5d1d52c13e

URL: https://github.com/llvm/llvm-project/commit/17e293d5b8f1e4486606127f2bc2fa5d1d52c13e
DIFF: https://github.com/llvm/llvm-project/commit/17e293d5b8f1e4486606127f2bc2fa5d1d52c13e.diff

LOG: [LLVM][AArch64]CFINV - Add UNPREDICTABLE behaviour if CRm is not zero (#140593)

Now CFINV follows AXFLAGS behaviour for CRm.

It looks like (0) in the instruction encoding means that the behaviour
is UNPREDICTABLE if that bit is not zero.

Added: 
    

Modified: 
    llvm/lib/Target/AArch64/AArch64InstrInfo.td
    llvm/test/MC/Disassembler/AArch64/armv8.4a-flag.txt

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index 010c7c391527f..22ecf99b12de6 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -2096,6 +2096,7 @@ def FJCVTZS  : BaseFPToIntegerUnscaled<0b01, 0b11, 0b110, FPR64, GPR32,
 let Predicates = [HasFlagM], Defs = [NZCV], Uses = [NZCV] in {
 def CFINV : SimpleSystemI<0, (ins), "cfinv", "">, Sched<[WriteSys]> {
   let Inst{20-5} = 0b0000001000000000;
+  let Unpredictable{11-8} = 0b1111;
 }
 def SETF8  : BaseFlagManipulation<0, 0, (ins GPR32:$Rn), "setf8", "{\t$Rn}">;
 def SETF16 : BaseFlagManipulation<0, 1, (ins GPR32:$Rn), "setf16", "{\t$Rn}">;

diff  --git a/llvm/test/MC/Disassembler/AArch64/armv8.4a-flag.txt b/llvm/test/MC/Disassembler/AArch64/armv8.4a-flag.txt
index c29109d578f2c..1f12c2cca0de1 100644
--- a/llvm/test/MC/Disassembler/AArch64/armv8.4a-flag.txt
+++ b/llvm/test/MC/Disassembler/AArch64/armv8.4a-flag.txt
@@ -2,10 +2,12 @@
 # RUN: llvm-mc -triple aarch64-none-linux-gnu -mattr=+v8r --disassemble < %s | FileCheck %s
 
 [0x1f,0x40,0x00,0xd5]
+[0x1f,0x4f,0x00,0xd5]
 [0x2d,0x08,0x00,0x3a]
 [0x2d,0x48,0x00,0x3a]
 [0x2f,0x84,0x1f,0xba]
 
+#CHECK:  cfinv
 #CHECK:  cfinv
 #CHECK:  setf8  w1
 #CHECK:  setf16  w1