[llvm-commits] [llvm] r161262 - in /llvm/trunk: lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp test/CodeGen/X86/memcmp.ll tools/llc/llc.cpp

[Bob Wilson]

Author: bwilson
Date: Fri Aug  3 16:26:18 2012
New Revision: 161262

URL: http://llvm.org/viewvc/llvm-project?rev=161262&view=rev
Log:
Fix memcmp code-gen to honor -fno-builtin.

I noticed that SelectionDAGBuilder::visitCall was missing a check for memcmp
in TargetLibraryInfo, so that it would use custom code for memcmp calls even
with -fno-builtin.  I also had to add a new -disable-simplify-libcalls option
to llc so that I could write a test for this.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    llvm/trunk/test/CodeGen/X86/memcmp.ll
    llvm/trunk/tools/llc/llc.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=161262&r1=161261&r2=161262&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Fri Aug  3 16:26:18 2012
@@ -5682,7 +5682,7 @@
                                    Tmp.getValueType(), Tmp));
           return;
         }
-      } else if (Name == "memcmp") {
+      } else if ((LibInfo->has(LibFunc::memcmp) && Name == "memcmp")) {
         if (visitMemCmpCall(I))
           return;
       }

Modified: llvm/trunk/test/CodeGen/X86/memcmp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/memcmp.ll?rev=161262&r1=161261&r2=161262&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/memcmp.ll (original)
+++ llvm/trunk/test/CodeGen/X86/memcmp.ll Fri Aug  3 16:26:18 2012
@@ -1,4 +1,5 @@
 ; RUN: llc < %s -mtriple=x86_64-linux | FileCheck %s
+; RUN: llc < %s -disable-simplify-libcalls -mtriple=x86_64-linux | FileCheck %s --check-prefix=NOBUILTIN
 ; RUN: llc < %s -mtriple=x86_64-win32 | FileCheck %s
 
 ; This tests codegen time inlining/optimization of memcmp
@@ -23,6 +24,8 @@
 ; CHECK: memcmp2:
 ; CHECK: movw    ([[A0:%rdi|%rcx]]), %ax
 ; CHECK: cmpw    ([[A1:%rsi|%rdx]]), %ax
+; NOBUILTIN: memcmp2:
+; NOBUILTIN: callq
 }
 
 define void @memcmp2a(i8* %X, i32* nocapture %P) nounwind {

Modified: llvm/trunk/tools/llc/llc.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llc/llc.cpp?rev=161262&r1=161261&r2=161262&view=diff
==============================================================================
--- llvm/trunk/tools/llc/llc.cpp (original)
+++ llvm/trunk/tools/llc/llc.cpp Fri Aug  3 16:26:18 2012
@@ -35,6 +35,7 @@
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Target/TargetData.h"
+#include "llvm/Target/TargetLibraryInfo.h"
 #include "llvm/Target/TargetMachine.h"
 #include <memory>
 using namespace llvm;
@@ -214,6 +215,11 @@
   cl::init(false));
 
 static cl::opt<bool>
+DisableSimplifyLibCalls("disable-simplify-libcalls",
+  cl::desc("Disable simplify-libcalls"),
+  cl::init(false));
+
+static cl::opt<bool>
 EnableGuaranteedTailCallOpt("tailcallopt",
   cl::desc("Turn fastcc calls into tail calls by (potentially) changing ABI."),
   cl::init(false));
@@ -487,6 +493,12 @@
   // Build up all of the passes that we want to do to the module.
   PassManager PM;
 
+  // Add an appropriate TargetLibraryInfo pass for the module's triple.
+  TargetLibraryInfo *TLI = new TargetLibraryInfo(TheTriple);
+  if (DisableSimplifyLibCalls)
+    TLI->disableAllFunctions();
+  PM.add(TLI);
+
   // Add the target data from the target machine, if it exists, or the module.
   if (const TargetData *TD = Target.getTargetData())
     PM.add(new TargetData(*TD));