[llvm] r243290 - Reset the virtual registers in liveins when clearing the virtual registers.

[Alex Lorenz]

Author: arphaman
Date: Mon Jul 27 12:51:59 2015
New Revision: 243290

URL: http://llvm.org/viewvc/llvm-project?rev=243290&view=rev
Log:
Reset the virtual registers in liveins when clearing the virtual registers.

This commit zeroes out the virtual register references in the machine
function's liveins in the class 'MachineRegisterInfo' when the virtual
register definitions are cleared.

Reviewers: Matthias Braun

Added:
    llvm/trunk/test/CodeGen/X86/virtual-registers-cleared-in-machine-functions-liveins.ll
Modified:
    llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp

Modified: llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp?rev=243290&r1=243289&r2=243290&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineRegisterInfo.cpp Mon Jul 27 12:51:59 2015
@@ -116,6 +116,8 @@ void MachineRegisterInfo::clearVirtRegs(
   }
 #endif
   VRegInfo.clear();
+  for (auto &I : LiveIns)
+    I.second = 0;
 }
 
 void MachineRegisterInfo::verifyUseList(unsigned Reg) const {

Added: llvm/trunk/test/CodeGen/X86/virtual-registers-cleared-in-machine-functions-liveins.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/virtual-registers-cleared-in-machine-functions-liveins.ll?rev=243290&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/virtual-registers-cleared-in-machine-functions-liveins.ll (added)
+++ llvm/trunk/test/CodeGen/X86/virtual-registers-cleared-in-machine-functions-liveins.ll Mon Jul 27 12:51:59 2015
@@ -0,0 +1,19 @@
+; RUN: llc -march=x86-64 -o /dev/null -stop-after machine-scheduler %s | FileCheck %s --check-prefix=PRE-RA
+; RUN: llc -march=x86-64 -o /dev/null -stop-after prologepilog %s | FileCheck %s --check-prefix=POST-RA
+
+; This test verifies that the virtual register references in machine function's
+; liveins are cleared after register allocation.
+
+define i32 @test(i32 %a, i32 %b) {
+body:
+  %c = mul i32 %a, %b
+  ret i32 %c
+}
+
+; PRE-RA: liveins:
+; PRE-RA-NEXT: - { reg: '%edi', virtual-reg: '%0' }
+; PRE-RA-NEXT: - { reg: '%esi', virtual-reg: '%1' }
+
+; POST-RA: liveins:
+; POST-RA-NEXT: - { reg: '%edi' }
+; POST-RA-NEXT: - { reg: '%esi' }