Follow the implementation approach suggested by PR6687,

which generates more efficient and more obviously conformant
code.  We now test for overflow of the multiply then force
the result to -1 if so.  On X86, this generates nice code
like this:

__Z4testl:                              ## @_Z4testl
## BB#0:                                ## %entry
	subl	$12, %esp
	movl	$4, %eax
	mull	16(%esp)
	testl	%edx, %edx
	movl	$-1, %ecx
	cmovel	%eax, %ecx
	movl	%ecx, (%esp)
	call	__Znam
	addl	$12, %esp
	ret

llvm-svn: 108927

1 files changed, 1 insertions, 5 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 1a117cab962..f236eb42538 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -656,7 +656,7 @@ private:
 
   llvm::BasicBlock *TerminateLandingPad;
   llvm::BasicBlock *TerminateHandler;
-  llvm::BasicBlock *TrapBB, *ThrowLengthErrorBB;
+  llvm::BasicBlock *TrapBB;
 
 public:
   CodeGenFunction(CodeGenModule &cgm);
@@ -1544,10 +1544,6 @@ public:
   /// generate a branch around the created basic block as necessary.
   llvm::BasicBlock *getTrapBB();
   
-  /// getThrowLengthErrorBB - Create a basic block that will call
-  /// std::__throw_length_error to throw a std::length_error exception.
-  llvm::BasicBlock *getThrowLengthErrorBB();
-  
   /// EmitCallArg - Emit a single call argument.
   RValue EmitCallArg(const Expr *E, QualType ArgType);