[PATCH] D78151: [AArch64InstrInfo] Ignore debug insts in canInstrSubstituteCmpInstr

[Vedant Kumar via Phabricator via llvm-commits]

vsk updated this revision to Diff 257842.
vsk added a comment.

Introduce a range helper to visit instructions (skipping debug insts)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D78151/new/

https://reviews.llvm.org/D78151

Files:
  llvm/include/llvm/CodeGen/MachineBasicBlock.h
  llvm/lib/CodeGen/PeepholeOptimizer.cpp
  llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
  llvm/test/CodeGen/AArch64/arm64-arm64-dead-def-elimination-flag.ll


Index: llvm/test/CodeGen/AArch64/arm64-arm64-dead-def-elimination-flag.ll
===================================================================
--- llvm/test/CodeGen/AArch64/arm64-arm64-dead-def-elimination-flag.ll
+++ llvm/test/CodeGen/AArch64/arm64-arm64-dead-def-elimination-flag.ll
@@ -1,4 +1,4 @@
-; RUN: llc -mtriple=arm64-apple-ios7.0.0 -aarch64-enable-dead-defs=false < %s | FileCheck %s
+; RUN: llc -debugify-and-strip-all-safe -mtriple=arm64-apple-ios7.0.0 -aarch64-enable-dead-defs=false < %s | FileCheck %s
 
 target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
 
Index: llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -1443,10 +1443,9 @@
     return false;
 
   UsedNZCV NZCVUsedAfterCmp;
-  for (auto I = std::next(CmpInstr->getIterator()),
-            E = CmpInstr->getParent()->instr_end();
-       I != E; ++I) {
-    const MachineInstr &Instr = *I;
+  for (const MachineInstr &Instr :
+       instructionsWithoutDebug(std::next(CmpInstr->getIterator()),
+                                CmpInstr->getParent()->instr_end())) {
     if (Instr.readsRegister(AArch64::NZCV, TRI)) {
       AArch64CC::CondCode CC = findCondCodeUsedByInstr(Instr);
       if (CC == AArch64CC::Invalid) // Unsupported conditional instruction
Index: llvm/lib/CodeGen/PeepholeOptimizer.cpp
===================================================================
--- llvm/lib/CodeGen/PeepholeOptimizer.cpp
+++ llvm/lib/CodeGen/PeepholeOptimizer.cpp
@@ -614,6 +614,7 @@
     return false;
 
   // Attempt to optimize the comparison instruction.
+  LLVM_DEBUG(dbgs() << "Attempting to optimize compare: " << MI);
   if (TII->optimizeCompareInstr(MI, SrcReg, SrcReg2, CmpMask, CmpValue, MRI)) {
     ++NumCmps;
     return true;
@@ -635,6 +636,7 @@
     return false;
   if (!TII->optimizeSelect(MI, LocalMIs))
     return false;
+  LLVM_DEBUG(dbgs() << "Deleting select: " << MI);
   MI.eraseFromParent();
   ++NumSelects;
   return true;
@@ -1299,6 +1301,7 @@
   }
 
   // MI is now dead.
+  LLVM_DEBUG(dbgs() << "Deleting uncoalescable copy: " << MI);
   MI.eraseFromParent();
   ++NumUncoalescableCopies;
   return true;
@@ -1723,6 +1726,7 @@
           (foldRedundantCopy(*MI, CopySrcRegs, CopySrcMIs) ||
            foldRedundantNAPhysCopy(*MI, NAPhysToVirtMIs))) {
         LocalMIs.erase(MI);
+        LLVM_DEBUG(dbgs() << "Deleting redundant copy: " << *MI << "\n");
         MI->eraseFromParent();
         Changed = true;
         continue;
Index: llvm/include/llvm/CodeGen/MachineBasicBlock.h
===================================================================
--- llvm/include/llvm/CodeGen/MachineBasicBlock.h
+++ llvm/include/llvm/CodeGen/MachineBasicBlock.h
@@ -1061,6 +1061,23 @@
   return It;
 }
 
+/// Construct a range iterator which begins at \p It and moves forwards until
+/// \p End is reached, skipping any debug instructions.
+template <typename IterT>
+inline auto instructionsWithoutDebug(IterT It, IterT End) {
+  return make_filter_range(make_range(It, End), [](const MachineInstr &MI) {
+    return !MI.isDebugInstr();
+  });
+}
+
+/// Construct a range iterator which begins at \p It and moves backwards until
+/// \p Begin is reached, skipping any debug instructions.
+template <typename IterT>
+inline auto reversedInstructionsWithoutDebug(IterT It, IterT Begin) {
+  return instructionsWithoutDebug(make_reverse_iterator(It),
+                                  make_reverse_iterator(Begin));
+}
+
 } // end namespace llvm
 
 #endif // LLVM_CODEGEN_MACHINEBASICBLOCK_H


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D78151.257842.patch
Type: text/x-patch
Size: 3655 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200415/656513f3/attachment.bin>