r206543 - BackendUtil: Pass through -mdisable-tail-calls

[Duncan P. N. Exon Smith]

Author: dexonsmith
Date: Thu Apr 17 20:05:25 2014
New Revision: 206543

URL: http://llvm.org/viewvc/llvm-project?rev=206543&view=rev
Log:
BackendUtil: Pass through -mdisable-tail-calls

The frontend option -fno-optimize-sibling-calls resolves to -cc1's
-mdisable-tail-calls, which is passed to the TargetMachine in the
backend.  PassManagerBuilder was adding the -tailcallelim pass anyway.

Use a new DisableTailCalls option in PassManagerBuilder to disable tail
calls harder.

Requires the matching commit in LLVM that adds DisableTailCalls.

<rdar://problem/16050591>

Added:
    cfe/trunk/test/CodeGen/disable-tail-calls.c
Modified:
    cfe/trunk/lib/CodeGen/BackendUtil.cpp

Modified: cfe/trunk/lib/CodeGen/BackendUtil.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/BackendUtil.cpp?rev=206543&r1=206542&r2=206543&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/BackendUtil.cpp (original)
+++ cfe/trunk/lib/CodeGen/BackendUtil.cpp Thu Apr 17 20:05:25 2014
@@ -247,6 +247,7 @@ void EmitAssemblyHelper::CreatePasses()
   PMBuilder.SLPVectorize = CodeGenOpts.VectorizeSLP;
   PMBuilder.LoopVectorize = CodeGenOpts.VectorizeLoop;
 
+  PMBuilder.DisableTailCalls = CodeGenOpts.DisableTailCalls;
   PMBuilder.DisableUnitAtATime = !CodeGenOpts.UnitAtATime;
   PMBuilder.DisableUnrollLoops = !CodeGenOpts.UnrollLoops;
   PMBuilder.RerollLoops = CodeGenOpts.RerollLoops;

Added: cfe/trunk/test/CodeGen/disable-tail-calls.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/disable-tail-calls.c?rev=206543&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/disable-tail-calls.c (added)
+++ cfe/trunk/test/CodeGen/disable-tail-calls.c Thu Apr 17 20:05:25 2014
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9.0 -emit-llvm -O1 -mdisable-tail-calls -o - < %s | FileCheck %s
+
+typedef struct List {
+  struct List *next;
+  int data;
+} List;
+
+// CHECK-LABEL: define %struct.List* @find
+List *find(List *head, int data) {
+  if (!head)
+    return 0;
+  if (head->data == data)
+    return head;
+  // CHECK: call %struct.List* @find
+  return find(head->next, data);
+}