[llvm-branch-commits] [llvm-branch] r324466 - Merging r324422:

[Hans Wennborg via llvm-branch-commits]

Author: hans
Date: Wed Feb  7 02:01:03 2018
New Revision: 324466

URL: http://llvm.org/viewvc/llvm-project?rev=324466&view=rev
Log:
Merging r324422:
------------------------------------------------------------------------
r324422 | efriedma | 2018-02-07 00:00:17 +0100 (Wed, 07 Feb 2018) | 16 lines

[LivePhysRegs] Fix handling of return instructions.

See D42509 for the original version of this.

Basically, there are two significant changes to behavior here:

- addLiveOuts always adds all pristine registers (even if a block has
no successors).
- addLiveOuts and addLiveOutsNoPristines always add all callee-saved
registers for return blocks (including conditional return blocks).

I cleaned up the functions a bit to make it clear these properties hold.

Differential Revision: https://reviews.llvm.org/D42655


------------------------------------------------------------------------

Added:
    llvm/branches/release_60/test/CodeGen/Thumb/stm-scavenging.ll
      - copied unchanged from r324422, llvm/trunk/test/CodeGen/Thumb/stm-scavenging.ll
Modified:
    llvm/branches/release_60/   (props changed)
    llvm/branches/release_60/lib/CodeGen/LivePhysRegs.cpp
    llvm/branches/release_60/test/CodeGen/ARM/pr25838.ll

Propchange: llvm/branches/release_60/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Wed Feb  7 02:01:03 2018
@@ -1,3 +1,3 @@
 /llvm/branches/Apple/Pertwee:110850,110961
 /llvm/branches/type-system-rewrite:133420-134817
-/llvm/trunk:155241,321751,321789,321791,321806,321862,321870,321872,321878,321980,321991,321993-321994,322003,322016,322053,322056,322103,322106,322108,322123,322131,322223,322272,322313,322372,322473,322623,322644,322724,322767,322875,322878-322879,322900,322904-322905,322973,322993,323034,323155,323190,323307,323331,323355,323369,323371,323384,323469,323515,323536,323582,323643,323671-323672,323706,323710,323759,323781,323810-323811,323813,323857,323907-323909,323913,323915,324002,324039
+/llvm/trunk:155241,321751,321789,321791,321806,321862,321870,321872,321878,321980,321991,321993-321994,322003,322016,322053,322056,322103,322106,322108,322123,322131,322223,322272,322313,322372,322473,322623,322644,322724,322767,322875,322878-322879,322900,322904-322905,322973,322993,323034,323155,323190,323307,323331,323355,323369,323371,323384,323469,323515,323536,323582,323643,323671-323672,323706,323710,323759,323781,323810-323811,323813,323857,323907-323909,323913,323915,324002,324039,324422

Modified: llvm/branches/release_60/lib/CodeGen/LivePhysRegs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_60/lib/CodeGen/LivePhysRegs.cpp?rev=324466&r1=324465&r2=324466&view=diff
==============================================================================
--- llvm/branches/release_60/lib/CodeGen/LivePhysRegs.cpp (original)
+++ llvm/branches/release_60/lib/CodeGen/LivePhysRegs.cpp Wed Feb  7 02:01:03 2018
@@ -205,14 +205,18 @@ void LivePhysRegs::addPristines(const Ma
 }
 
 void LivePhysRegs::addLiveOutsNoPristines(const MachineBasicBlock &MBB) {
-  if (!MBB.succ_empty()) {
-    // To get the live-outs we simply merge the live-ins of all successors.
-    for (const MachineBasicBlock *Succ : MBB.successors())
-      addBlockLiveIns(*Succ);
-  } else if (MBB.isReturnBlock()) {
-    // For the return block: Add all callee saved registers that are saved and
-    // restored (somewhere); This does not include callee saved registers that
-    // are unused and hence not saved and restored; they are called pristine.
+  // To get the live-outs we simply merge the live-ins of all successors.
+  for (const MachineBasicBlock *Succ : MBB.successors())
+    addBlockLiveIns(*Succ);
+  if (MBB.isReturnBlock()) {
+    // Return blocks are a special case because we currently don't mark up
+    // return instructions completely: specifically, there is no explicit
+    // use for callee-saved registers. So we add all callee saved registers
+    // that are saved and restored (somewhere). This does not include
+    // callee saved registers that are unused and hence not saved and
+    // restored; they are called pristine.
+    // FIXME: PEI should add explicit markings to return instructions
+    // instead of implicitly handling them here.
     const MachineFunction &MF = *MBB.getParent();
     const MachineFrameInfo &MFI = MF.getFrameInfo();
     if (MFI.isCalleeSavedInfoValid()) {
@@ -225,15 +229,8 @@ void LivePhysRegs::addLiveOutsNoPristine
 
 void LivePhysRegs::addLiveOuts(const MachineBasicBlock &MBB) {
   const MachineFunction &MF = *MBB.getParent();
-  if (!MBB.succ_empty()) {
-    addPristines(MF);
-    addLiveOutsNoPristines(MBB);
-  } else if (MBB.isReturnBlock()) {
-    // For the return block: Add all callee saved registers.
-    const MachineFrameInfo &MFI = MF.getFrameInfo();
-    if (MFI.isCalleeSavedInfoValid())
-      addCalleeSavedRegs(*this, MF);
-  }
+  addPristines(MF);
+  addLiveOutsNoPristines(MBB);
 }
 
 void LivePhysRegs::addLiveIns(const MachineBasicBlock &MBB) {

Modified: llvm/branches/release_60/test/CodeGen/ARM/pr25838.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_60/test/CodeGen/ARM/pr25838.ll?rev=324466&r1=324465&r2=324466&view=diff
==============================================================================
--- llvm/branches/release_60/test/CodeGen/ARM/pr25838.ll (original)
+++ llvm/branches/release_60/test/CodeGen/ARM/pr25838.ll Wed Feb  7 02:01:03 2018
@@ -1,4 +1,4 @@
-; RUN: llc < %s
+; RUN: llc -verify-machineinstrs < %s
 ; PR25838
 
 target triple = "armv7--linux-android"