[llvm-commits] [llvm] r151200 - in /llvm/trunk: include/llvm/CodeGen/AsmPrinter.h lib/CodeGen/AsmPrinter/AsmPrinter.cpp lib/Target/PowerPC/PPCAsmPrinter.cpp test/CodeGen/PowerPC/ppc64-linux-func-size.ll

[Hal Finkel]

Author: hfinkel
Date: Wed Feb 22 15:11:47 2012
New Revision: 151200

URL: http://llvm.org/viewvc/llvm-project?rev=151200&view=rev
Log:
Allow the use of an alternate symbol for calculating a function's size.

The standard function epilog includes a .size directive, but ppc64 uses
an alternate local symbol to tag the actual start of each function.

Until recently, binutils accepted the .size directive as:
 .size	test1, .Ltmp0-test1
however, using this directive with recent binutils will result in the error:
 .size expression for XXX does not evaluate to a constant
so we must use the label which actually tags the start of the function.

Added:
    llvm/trunk/test/CodeGen/PowerPC/ppc64-linux-func-size.ll
Modified:
    llvm/trunk/include/llvm/CodeGen/AsmPrinter.h
    llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
    llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp

Modified: llvm/trunk/include/llvm/CodeGen/AsmPrinter.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/AsmPrinter.h?rev=151200&r1=151199&r2=151200&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/AsmPrinter.h (original)
+++ llvm/trunk/include/llvm/CodeGen/AsmPrinter.h Wed Feb 22 15:11:47 2012
@@ -88,6 +88,11 @@
     ///
     MCSymbol *CurrentFnSym;
 
+    /// The symbol used to represent the start of the current function for the
+    /// purpose of calculating its size (e.g. using the .size directive). By
+    /// default, this is equal to CurrentFnSym.
+    MCSymbol *CurrentFnSymForSize;
+
   private:
     // GCMetadataPrinters - The garbage collection metadata printer table.
     void *GCMetadataPrinters;  // Really a DenseMap.

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp?rev=151200&r1=151199&r2=151200&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp Wed Feb 22 15:11:47 2012
@@ -100,6 +100,7 @@
     OutStreamer(Streamer),
     LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
   DD = 0; DE = 0; MMI = 0; LI = 0;
+  CurrentFnSym = CurrentFnSymForSize = 0;
   GCMetadataPrinters = 0;
   VerboseAsm = Streamer.isVerboseAsm();
 }
@@ -761,7 +762,8 @@
 
     const MCExpr *SizeExp =
       MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
-                              MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
+                              MCSymbolRefExpr::Create(CurrentFnSymForSize,
+                                                      OutContext),
                               OutContext);
     OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
   }
@@ -951,6 +953,7 @@
   this->MF = &MF;
   // Get the function symbol.
   CurrentFnSym = Mang->getSymbol(MF.getFunction());
+  CurrentFnSymForSize = CurrentFnSym;
 
   if (isVerbose())
     LI = &getAnalysis<MachineLoopInfo>();

Modified: llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp?rev=151200&r1=151199&r2=151200&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp Wed Feb 22 15:11:47 2012
@@ -398,7 +398,11 @@
   OutStreamer.EmitRawText("\t.quad .L." + Twine(CurrentFnSym->getName()) +
                           ",.TOC. at tocbase");
   OutStreamer.EmitRawText(StringRef("\t.previous"));
-  OutStreamer.EmitRawText(".L." + Twine(CurrentFnSym->getName()) + ":");
+
+  MCSymbol *RealFnSym = OutContext.GetOrCreateSymbol(
+                          ".L." + Twine(CurrentFnSym->getName()));
+  OutStreamer.EmitLabel(RealFnSym);
+  CurrentFnSymForSize = RealFnSym;
 }
 
 

Added: llvm/trunk/test/CodeGen/PowerPC/ppc64-linux-func-size.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/ppc64-linux-func-size.ll?rev=151200&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/ppc64-linux-func-size.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/ppc64-linux-func-size.ll Wed Feb 22 15:11:47 2012
@@ -0,0 +1,18 @@
+; RUN: llc < %s -mtriple=powerpc64-unknown-linux-gnu -mcpu=g5 | FileCheck %s
+
+; CHECK: test1:
+; CHECK-NEXT:	.quad .L.test1,.TOC. at tocbase
+; CHECK-NEXT:	.previous
+; CHECK-NEXT: .L.test1:
+
+define i32 @test1(i32 %a) nounwind {
+entry:
+  ret i32 %a
+}
+
+; Until recently, binutils accepted the .size directive as:
+;  .size	test1, .Ltmp0-test1
+; however, using this directive with recent binutils will result in the error:
+;  .size expression for XXX does not evaluate to a constant
+; so we must use the label which actually tags the start of the function.
+; CHECK: .size	test1, .Ltmp0-.L.test1