[PATCH] D57314: [PowerPC] more opportunity for converting reg+reg to reg+imm

[ChenZheng via Phabricator via llvm-commits]

shchenz updated this revision to Diff 184002.
shchenz added a comment.

Thanks for your comment @stefanp. Updated.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57314/new/

https://reviews.llvm.org/D57314

Files:
  llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
  llvm/test/CodeGen/PowerPC/convert-rr-to-ri-instr-add.mir


Index: llvm/test/CodeGen/PowerPC/convert-rr-to-ri-instr-add.mir
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/PowerPC/convert-rr-to-ri-instr-add.mir
@@ -0,0 +1,17 @@
+# RUN: llc -mtriple=powerpc64le--linux-gnu -stop-after ppc-pre-emit-peephole %s -o - -verify-machineinstrs | FileCheck %s
+
+---
+; ADDI8 + STFSX can be converted to ADDI8 + STFS even ADDI8 can not be erased.
+name: testFwdOperandKilledAfter
+# CHECK: name: testFwdOperandKilledAfter
+tracksRegLiveness: true 
+body: |
+  bb.0.entry:
+    liveins: $x3, $f1, $x5  
+    $x3 = ADDI8 $x5, 100  
+    STFSX killed $f1, $zero8, $x3  
+    ; CHECK: STFS killed $f1, 100, $x5  
+    STD killed $x3, killed $x5, 100  
+    ; CHECK: STD killed $x3, killed $x5, 100  
+    BLR8 implicit $lr8, implicit $rm 
+...
Index: llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
+++ llvm/lib/Target/PowerPC/PPCInstrInfo.cpp
@@ -3205,9 +3205,9 @@
   }
   assert((&*It) == &DefMI && "DefMI is missing");
 
-  // If DefMI also uses the register to be forwarded, we can only forward it
+  // If DefMI also defines the register to be forwarded, we can only forward it
   // if DefMI is being erased.
-  if (DefMI.readsRegister(Reg, &getRegisterInfo()))
+  if (DefMI.modifiesRegister(Reg, &getRegisterInfo()))
     return KillDefMI;
 
   return true;


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D57314.184002.patch
Type: text/x-patch
Size: 1454 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190129/607705b1/attachment.bin>