From 44248e0f631beec23db16fa62ddfd799492ea3ff Mon Sep 17 00:00:00 2001
From: Tom Stellard <thomas.stellard@amd.com>
Date: Mon, 18 Nov 2013 19:43:38 +0000
Subject: [PATCH] R600: Fix a crash in the AMDILCFGStrucurizer

The ifPatternMatch() function was not correctly reporting the number
of matches in some cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195030 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/R600/AMDILCFGStructurizer.cpp | 13 ++---
 test/CodeGen/R600/structurize1.ll        | 62 ++++++++++++++++++++++++
 2 files changed, 69 insertions(+), 6 deletions(-)
 create mode 100644 test/CodeGen/R600/structurize1.ll

diff --git a/lib/Target/R600/AMDILCFGStructurizer.cpp b/lib/Target/R600/AMDILCFGStructurizer.cpp
index beaaba86dae..507570fdcaa 100644
--- a/lib/Target/R600/AMDILCFGStructurizer.cpp
+++ b/lib/Target/R600/AMDILCFGStructurizer.cpp
@@ -1005,13 +1005,14 @@ int AMDGPUCFGStructurizer::ifPatternMatch(MachineBasicBlock *MBB) {
     return 0;
 
   assert(isCondBranch(BranchMI));
+  int NumMatch = 0;
 
   MachineBasicBlock *TrueMBB = getTrueBranch(BranchMI);
-  serialPatternMatch(TrueMBB);
-  ifPatternMatch(TrueMBB);
+  NumMatch += serialPatternMatch(TrueMBB);
+  NumMatch += ifPatternMatch(TrueMBB);
   MachineBasicBlock *FalseMBB = getFalseBranch(MBB, BranchMI);
-  serialPatternMatch(FalseMBB);
-  ifPatternMatch(FalseMBB);
+  NumMatch += serialPatternMatch(FalseMBB);
+  NumMatch += ifPatternMatch(FalseMBB);
   MachineBasicBlock *LandBlk;
   int Cloned = 0;
 
@@ -1040,7 +1041,7 @@ int AMDGPUCFGStructurizer::ifPatternMatch(MachineBasicBlock *MBB) {
     && isSameloopDetachedContbreak(FalseMBB, TrueMBB)) {
     LandBlk = *TrueMBB->succ_begin();
   } else {
-    return handleJumpintoIf(MBB, TrueMBB, FalseMBB);
+    return NumMatch + handleJumpintoIf(MBB, TrueMBB, FalseMBB);
   }
 
   // improveSimpleJumpinfoIf can handle the case where landBlk == NULL but the
@@ -1068,7 +1069,7 @@ int AMDGPUCFGStructurizer::ifPatternMatch(MachineBasicBlock *MBB) {
 
   numClonedBlock += Cloned;
 
-  return 1 + Cloned;
+  return 1 + Cloned + NumMatch;
 }
 
 int AMDGPUCFGStructurizer::loopendPatternMatch() {
diff --git a/test/CodeGen/R600/structurize1.ll b/test/CodeGen/R600/structurize1.ll
new file mode 100644
index 00000000000..8c10301a168
--- /dev/null
+++ b/test/CodeGen/R600/structurize1.ll
@@ -0,0 +1,62 @@
+; RUN: llc < %s -march=r600 -mattr=disable-ifcvt -mcpu=redwood | FileCheck %s
+
+; This tests for abug where the AMDILCFGStructurizer was crashing on loops
+; like this:
+;
+; for (i = 0; i < x; i++) {
+;   if (cond0) {
+;     if (cond1) {
+;
+;     } else {
+;
+;     }
+;     if (cond2) {
+;
+;     }
+;   }
+; }
+
+; CHECK-LABEL: @if_inside_loop
+; CHECK: LOOP_START_DX10
+; CHECK: END_LOOP
+define void @if_inside_loop(i32 addrspace(1)* %out, i32 %a, i32 %b, i32 %c, i32 %d) {
+entry:
+  br label %for.body
+
+for.body:
+  %0 = phi i32 [0, %entry], [%inc, %for.inc]
+  %val = phi i32 [0, %entry], [%val.for.inc, %for.inc]
+  %inc = add i32 %0, 1
+  %1 = icmp ult i32 10, %a
+  br i1 %1, label %for.inc, label %if.then
+
+if.then:
+  %2 = icmp ne i32 0, %b
+  br i1 %2, label %if.then.true, label %if.then.false
+
+if.then.true:
+  %3 = add i32 %a, %val
+  br label %if
+
+if.then.false:
+  %4 = mul i32 %a, %val
+  br label %if
+
+if:
+  %val.if = phi i32 [%3, %if.then.true], [%4, %if.then.false]
+  %5 = icmp ne i32 0, %c
+  br i1 %5, label %if.true, label %for.inc
+
+if.true:
+  %6 = add i32 %a, %val.if
+  br label %for.inc
+
+for.inc:
+  %val.for.inc = phi i32 [%val, %for.body], [%val.if, %if], [%6, %if.true]
+  %7 = icmp ne i32 0, %d
+  br i1 %7, label %for.body, label %exit
+
+exit:
+  store i32 %val.for.inc, i32 addrspace(1)* %out
+  ret void
+}
-- 
2.34.1