From fe4f9d5977f58f25a2df0515e796e71686701b2f Mon Sep 17 00:00:00 2001
From: Akira Hatanaka <ahatanak@gmail.com>
Date: Fri, 20 May 2011 02:30:51 +0000
Subject: [PATCH] Fix bug in which nodes that write to argument registers do
 not get glued with the JALR node. Patch by Sasa Stankovic

llvm-svn: 131714
---
 llvm/lib/Target/Mips/MipsISelLowering.cpp | 23 ++++++++++++-----------
 llvm/test/CodeGen/Mips/i64arg.ll          | 10 +++++-----
 2 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/llvm/lib/Target/Mips/MipsISelLowering.cpp b/llvm/lib/Target/Mips/MipsISelLowering.cpp
index f9401858ce8c..ea26d57647f1 100644
--- a/llvm/lib/Target/Mips/MipsISelLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsISelLowering.cpp
@@ -1135,17 +1135,6 @@ MipsTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
     Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
                         &MemOpChains[0], MemOpChains.size());
 
-  // Build a sequence of copy-to-reg nodes chained together with token
-  // chain and flag operands which copy the outgoing args into registers.
-  // The InFlag in necessary since all emitted instructions must be
-  // stuck together.
-  SDValue InFlag;
-  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
-    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
-                             RegsToPass[i].second, InFlag);
-    InFlag = Chain.getValue(1);
-  }
-
   // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
   // direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
   // node so that legalize doesn't hack it.
@@ -1172,6 +1161,8 @@ MipsTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
     LoadSymAddr = true;
   }
 
+  SDValue InFlag;
+
   // Create nodes that load address of callee and copy it to T9
   if (IsPIC) {
     if (LoadSymAddr) {
@@ -1197,6 +1188,16 @@ MipsTargetLowering::LowerCall(SDValue Chain, SDValue Callee,
     Callee = DAG.getRegister(Mips::T9, MVT::i32);
   }
 
+  // Build a sequence of copy-to-reg nodes chained together with token
+  // chain and flag operands which copy the outgoing args into registers.
+  // The InFlag in necessary since all emitted instructions must be
+  // stuck together.
+  for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
+    Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
+                             RegsToPass[i].second, InFlag);
+    InFlag = Chain.getValue(1);
+  }
+
   // MipsJmpLink = #chain, #target_address, #opt_in_flags...
   //             = Chain, Callee, Reg#1, Reg#2, ...
   //
diff --git a/llvm/test/CodeGen/Mips/i64arg.ll b/llvm/test/CodeGen/Mips/i64arg.ll
index 8e8114b27c31..560f2e9b0874 100644
--- a/llvm/test/CodeGen/Mips/i64arg.ll
+++ b/llvm/test/CodeGen/Mips/i64arg.ll
@@ -4,24 +4,24 @@ define void @f1(i64 %ll1, float %f, i64 %ll, i32 %i, float %f2) nounwind {
 entry:
 ; CHECK: addu $[[R1:[0-9]+]], $zero, $5
 ; CHECK: addu $[[R0:[0-9]+]], $zero, $4
+; CHECK: lw  $25, %call16(ff1)
 ; CHECK: ori $6, ${{[0-9]+}}, 3855
 ; CHECK: ori $7, ${{[0-9]+}}, 22136
-; CHECK: lw  $25, %call16(ff1)
 ; CHECK: jalr
   tail call void @ff1(i32 %i, i64 1085102592623924856) nounwind
-; CHECK: lw $[[R2:[0-9]+]], 96($sp)
-; CHECK: lw $[[R3:[0-9]+]], 100($sp)
+; CHECK: lw $25, %call16(ff2)
+; CHECK: lw $[[R2:[0-9]+]], 88($sp)
+; CHECK: lw $[[R3:[0-9]+]], 92($sp)
 ; CHECK: addu $4, $zero, $[[R2]]
 ; CHECK: addu $5, $zero, $[[R3]]
-; CHECK: lw $25, %call16(ff2)
 ; CHECK: jalr $25
   tail call void @ff2(i64 %ll, double 3.000000e+00) nounwind
   %sub = add nsw i32 %i, -1
 ; CHECK: sw $[[R0]], 24($sp)
 ; CHECK: sw $[[R1]], 28($sp)
+; CHECK: lw $25, %call16(ff3)
 ; CHECK: addu $6, $zero, $[[R2]]
 ; CHECK: addu $7, $zero, $[[R3]]
-; CHECK: lw $25, %call16(ff3)
 ; CHECK: jalr $25
   tail call void @ff3(i32 %i, i64 %ll, i32 %sub, i64 %ll1) nounwind
   ret void