From 5236ab3fdd4ce9b9990ef58cd8fac695cfbd0eaf Mon Sep 17 00:00:00 2001
From: Roman Divacky <rdivacky@freebsd.org>
Date: Mon, 24 Sep 2012 20:47:19 +0000
Subject: [PATCH] Specify MachinePointerInfo as refering to the argument value
 and offset of the store when handling byval arguments. Thus preventing
 reordering of the store with load with post-RA scheduler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164553 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/PowerPC/PPCISelLowering.cpp |  8 +++++---
 test/CodeGen/PowerPC/pr13891.ll        | 27 ++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 3 deletions(-)
 create mode 100644 test/CodeGen/PowerPC/pr13891.ll

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 2e8fa1842aeb..239aa2bf4d04 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -2048,7 +2048,8 @@ PPCTargetLowering::LowerFormalArguments_Darwin_Or_64SVR4(
 
   SmallVector<SDValue, 8> MemOps;
   unsigned nAltivecParamsAtEnd = 0;
-  for (unsigned ArgNo = 0, e = Ins.size(); ArgNo != e; ++ArgNo) {
+  Function::const_arg_iterator FuncArg = MF.getFunction()->arg_begin();
+  for (unsigned ArgNo = 0, e = Ins.size(); ArgNo != e; ++ArgNo, ++FuncArg) {
     SDValue ArgVal;
     bool needsLoad = false;
     EVT ObjectVT = Ins[ArgNo].VT;
@@ -2103,7 +2104,8 @@ PPCTargetLowering::LowerFormalArguments_Darwin_Or_64SVR4(
           EVT ObjType = (ObjSize == 1 ? MVT::i8 :
                          (ObjSize == 2 ? MVT::i16 : MVT::i32));
           SDValue Store = DAG.getTruncStore(Val.getValue(1), dl, Val, FIN,
-                                            MachinePointerInfo(),
+                                            MachinePointerInfo(FuncArg,
+                                              CurArgOffset),
                                             ObjType, false, false, 0);
           MemOps.push_back(Store);
           ++GPR_idx;
@@ -2136,7 +2138,7 @@ PPCTargetLowering::LowerFormalArguments_Darwin_Or_64SVR4(
           }
 
           SDValue Store = DAG.getStore(Val.getValue(1), dl, Shifted, FIN,
-                                       MachinePointerInfo(),
+                                       MachinePointerInfo(FuncArg, ArgOffset),
                                        false, false, 0);
           MemOps.push_back(Store);
           ++GPR_idx;
diff --git a/test/CodeGen/PowerPC/pr13891.ll b/test/CodeGen/PowerPC/pr13891.ll
new file mode 100644
index 000000000000..3ae73850a342
--- /dev/null
+++ b/test/CodeGen/PowerPC/pr13891.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s | FileCheck %s
+target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+%struct.foo = type { i8, i8 }
+
+define void @_Z5check3foos(%struct.foo* nocapture byval %f, i16 signext %i) noinline {
+; CHECK: _Z5check3foos:
+; CHECK: sth 3, {{[0-9]+}}(1)
+; CHECK: lha {{[0-9]+}}, {{[0-9]+}}(1)
+entry:
+  %0 = bitcast %struct.foo* %f to i16*
+  %1 = load i16* %0, align 2
+  %bf.val.sext = ashr i16 %1, 8
+  %cmp = icmp eq i16 %bf.val.sext, %i
+  br i1 %cmp, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  %conv = sext i16 %bf.val.sext to i32
+  tail call void @exit(i32 %conv)
+  br label %if.end
+
+if.end:                                           ; preds = %entry, %if.then
+  ret void
+}
+
+declare void @exit(i32)