[PATCH] D110848: [TwoAddressInstruction] Fix ReplacedAllUntiedUses in processTiedPairs

[Jay Foad via Phabricator via llvm-commits]

foad updated this revision to Diff 376589.
foad added a comment.

Rebase on a test case that I will pre-commit.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D110848/new/

https://reviews.llvm.org/D110848

Files:
  llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
  llvm/test/CodeGen/SystemZ/twoaddr-kill.ll


Index: llvm/test/CodeGen/SystemZ/twoaddr-kill.ll
===================================================================
--- llvm/test/CodeGen/SystemZ/twoaddr-kill.ll
+++ llvm/test/CodeGen/SystemZ/twoaddr-kill.ll
@@ -1,8 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
 ; RUN: llc < %s -verify-machineinstrs -mtriple=s390x-linux-gnu -mcpu=z196 -stop-after=twoaddressinstruction -verify-machineinstrs | FileCheck %s
 
-; FIXME: The COPY from [[COPY3]] is killed even though there is a subsequent use
-; of [[COPY3]] in the INLINEASM instruction.
+; Check that the COPY from [[COPY3]] is not killed because there is a subsequent
+; use of [[COPY3]] in the INLINEASM instruction.
 define i32 @f2(i32 %old) {
   ; CHECK-LABEL: name: f2
   ; CHECK: bb.0 (%ir-block.0):
@@ -15,7 +15,7 @@
   ; CHECK-NEXT:   [[COPY2:%[0-9]+]]:grh32bit = COPY killed [[COPY1]]
   ; CHECK-NEXT:   INLINEASM &"stepa $1, $2, $3", 0 /* attdialect */, 393226 /* regdef:GRH32Bit */, def [[COPY2]], 2147483657 /* reguse tiedto:$0 */, [[COPY2]](tied-def 3), 9 /* reguse */, killed $r2l, 9 /* reguse */, killed $r3l
   ; CHECK-NEXT:   [[COPY3:%[0-9]+]]:grh32bit = COPY killed [[COPY2]]
-  ; CHECK-NEXT:   [[COPY4:%[0-9]+]]:grh32bit = COPY killed [[COPY3]]
+  ; CHECK-NEXT:   [[COPY4:%[0-9]+]]:grh32bit = COPY [[COPY3]]
   ; CHECK-NEXT:   INLINEASM &"stepb $1, $2", 0 /* attdialect */, 393227 /* regdef-ec:GRH32Bit */, def early-clobber [[COPY4]], 2147483657 /* reguse tiedto:$0 */, [[COPY4]](tied-def 3), 393225 /* reguse:GRH32Bit */, [[COPY3]]
   ; CHECK-NEXT:   $r2l = COPY killed [[COPY4]]
   ; CHECK-NEXT:   Return implicit killed $r2l
Index: llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
===================================================================
--- llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -1486,9 +1486,10 @@
   }
 
   if (AllUsesCopied) {
-    bool ReplacedAllUntiedUses = true;
+    bool ReplacedAllUntiedUses = false;
     if (!IsEarlyClobber) {
       // Replace other (un-tied) uses of regB with LastCopiedReg.
+      ReplacedAllUntiedUses = true;
       for (MachineOperand &MO : MI->operands()) {
         if (MO.isReg() && MO.getReg() == RegB && MO.isUse()) {
           if (MO.getSubReg() == SubRegB) {


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