[PATCH] D125237: [AArch64] Avoid emitting MOVID when NEON is disabled

[Alexander Richardson via Phabricator via llvm-commits]

arichardson created this revision.
arichardson added reviewers: SjoerdMeijer, MatzeB, dmgreen.
Herald added subscribers: hiraditya, kristof.beyls.
Herald added a project: All.
arichardson requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

Previously, creating a zero floating-point constant used MOVID even when
NEON was disabled which resulted in the following fatal error:
`Attempting to emit MOVID instruction but the Feature_HasNEON predicate(s) are not met`


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D125237

Files:
  llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
  llvm/test/CodeGen/AArch64/movid-no-neon.ll


Index: llvm/test/CodeGen/AArch64/movid-no-neon.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/movid-no-neon.ll
@@ -0,0 +1,42 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=aarch64 -mattr=+fullfp16,+neon -o - %s -O0 -filetype=asm | FileCheck %s --check-prefix=NEON-ENABLED
+; RUN: llc -mtriple=aarch64 -mattr=+fullfp16,-neon -o - %s -O0 -filetype=asm | FileCheck %s --check-prefix=NEON-DISABLED
+
+define float @get_float() {
+; NEON-ENABLED-LABEL: get_float:
+; NEON-ENABLED:       // %bb.0:
+; NEON-ENABLED-NEXT:    movi d0, #0000000000000000
+; NEON-ENABLED-NEXT:    ret
+;
+; NEON-DISABLED-LABEL: get_float:
+; NEON-DISABLED:       // %bb.0:
+; NEON-DISABLED-NEXT:    fmov s0, wzr
+; NEON-DISABLED-NEXT:    ret
+  ret float 0.000000e+00
+}
+
+define double @get_double() {
+; NEON-ENABLED-LABEL: get_double:
+; NEON-ENABLED:       // %bb.0:
+; NEON-ENABLED-NEXT:    movi d0, #0000000000000000
+; NEON-ENABLED-NEXT:    ret
+;
+; NEON-DISABLED-LABEL: get_double:
+; NEON-DISABLED:       // %bb.0:
+; NEON-DISABLED-NEXT:    fmov d0, xzr
+; NEON-DISABLED-NEXT:    ret
+  ret double 0.000000e+00
+}
+
+define half @get_half() {
+; NEON-ENABLED-LABEL: get_half:
+; NEON-ENABLED:       // %bb.0:
+; NEON-ENABLED-NEXT:    movi d0, #0000000000000000
+; NEON-ENABLED-NEXT:    ret
+;
+; NEON-DISABLED-LABEL: get_half:
+; NEON-DISABLED:       // %bb.0:
+; NEON-DISABLED-NEXT:    fmov h0, wzr
+; NEON-DISABLED-NEXT:    ret
+  ret half 0.000000e+00
+}
Index: llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -1129,7 +1129,8 @@
 
 void AArch64AsmPrinter::emitFMov0(const MachineInstr &MI) {
   Register DestReg = MI.getOperand(0).getReg();
-  if (STI->hasZeroCycleZeroingFP() && !STI->hasZeroCycleZeroingFPWorkaround()) {
+  if (STI->hasZeroCycleZeroingFP() && !STI->hasZeroCycleZeroingFPWorkaround() &&
+      STI->hasNEON()) {
     // Convert H/S register to corresponding D register
     if (AArch64::H0 <= DestReg && DestReg <= AArch64::H31)
       DestReg = AArch64::D0 + (DestReg - AArch64::H0);


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