[llvm-commits] [llvm] r95336 - in /llvm/trunk: lib/CodeGen/AsmPrinter/AsmPrinter.cpp test/CodeGen/PowerPC/2010-02-04-EmptyGlobal.ll

[Chris Lattner]

On Feb 4, 2010, at 4:17 PM, Bill Wendling wrote:

> Author: void
> Date: Thu Feb  4 18:17:02 2010
> New Revision: 95336
>
> URL: http://llvm.org/viewvc/llvm-project?rev=95336&view=rev
> Log:
> An empty global constant (one of size 0) may have a section  
> immediately
> following it. However, the EmitGlobalConstant method wasn't emitting  
> a body for
> the constant. The assembler doesn't like that. Before, we were  
> generating this:
>
>  .zerofill __DATA, __common, __cmd, 1, 3
>
> This fix puts us back to that semantic.

The patch looks good.  Please change the testcase to just contain the  
zero sized zero fill global and FileCheck for the .byte 0 after the  
label.

-Chris

>
> Added:
>    llvm/trunk/test/CodeGen/PowerPC/2010-02-04-EmptyGlobal.ll
> Modified:
>    llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
>
> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp?rev=95336&r1=95335&r2=95336&view=diff
>
> = 
> = 
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> = 
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> = 
> ======================================================================
> --- llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp (original)
> +++ llvm/trunk/lib/CodeGen/AsmPrinter/AsmPrinter.cpp Thu Feb  4  
> 18:17:02 2010
> @@ -1120,6 +1120,7 @@
> void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned  
> AddrSpace) {
>   if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
>     uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV- 
> >getType());
> +    if (Size == 0) Size = 1; // An empty "_foo:" followed by a  
> section is undef.
>     return OutStreamer.EmitZeros(Size, AddrSpace);
>   }
>
>
> Added: llvm/trunk/test/CodeGen/PowerPC/2010-02-04-EmptyGlobal.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/2010-02-04-EmptyGlobal.ll?rev=95336&view=auto
>
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> = 
> ======================================================================
> --- llvm/trunk/test/CodeGen/PowerPC/2010-02-04-EmptyGlobal.ll (added)
> +++ llvm/trunk/test/CodeGen/PowerPC/2010-02-04-EmptyGlobal.ll Thu  
> Feb  4 18:17:02 2010
> @@ -0,0 +1,50 @@
> +; RUN: llc < %s -mtriple=powerpc-apple-darwin10 -relocation- 
> model=pic -disable-fp-elim | FileCheck %s
> +; <rdar://problem/7604010>
> +
> +%struct.NSString = type opaque
> +%struct._DTOpaqueAssertStruct = type { }
> +%struct.objc_selector = type opaque
> +
> + at _cmd = constant %struct._DTOpaqueAssertStruct zeroinitializer ; < 
> %struct._DTOpaqueAssertStruct*> [#uses=1]
> + at OBJC_IMAGE_INFO = private constant [2 x i32] zeroinitializer,  
> section "__OBJC, __image_info,regular" ; <[2 x i32]*> [#uses=1]
> + at llvm.used = appending global [1 x i8*] [i8* bitcast ([2 x i32]*  
> @OBJC_IMAGE_INFO to i8*)], section "llvm.metadata" ; <[1 x i8*]*>  
> [#uses=0]
> +
> +define void @_DTAssertionFailureHandler(i8* %objp, i8* %selp, i32  
> %lineNumber, %struct.NSString* %msgFormat, ...) nounwind ssp {
> +entry:
> +  %objp_addr = alloca i8*                         ; <i8**> [#uses=1]
> +  %selp_addr = alloca i8*                         ; <i8**> [#uses=3]
> +  %lineNumber_addr = alloca i32                   ; <i32*> [#uses=1]
> +  %msgFormat_addr = alloca %struct.NSString*      ; < 
> %struct.NSString**> [#uses=1]
> +  %iftmp.0 = alloca %struct.objc_selector*        ; < 
> %struct.objc_selector**> [#uses=3]
> +  %sel = alloca %struct.objc_selector*            ; < 
> %struct.objc_selector**> [#uses=1]
> +  %"alloca point" = bitcast i32 0 to i32          ; <i32> [#uses=0]
> +  store i8* %objp, i8** %objp_addr
> +  store i8* %selp, i8** %selp_addr
> +  store i32 %lineNumber, i32* %lineNumber_addr
> +  store %struct.NSString* %msgFormat, %struct.NSString**  
> %msgFormat_addr
> +  %0 = load i8** %selp_addr, align 4              ; <i8*> [#uses=1]
> +  %1 = icmp ne i8* %0, bitcast (%struct._DTOpaqueAssertStruct*  
> @_cmd to i8*) ; <i1> [#uses=1]
> +  br i1 %1, label %bb, label %bb1
> +
> +bb:                                               ; preds = %entry
> +  %2 = load i8** %selp_addr, align 4              ; <i8*> [#uses=1]
> +  %3 = bitcast i8* %2 to %struct.objc_selector**  ; < 
> %struct.objc_selector**> [#uses=1]
> +  %4 = load %struct.objc_selector** %3, align 4   ; < 
> %struct.objc_selector*> [#uses=1]
> +  store %struct.objc_selector* %4, %struct.objc_selector** %iftmp. 
> 0, align 4
> +  br label %bb2
> +
> +bb1:                                              ; preds = %entry
> +  store %struct.objc_selector* null, %struct.objc_selector** %iftmp. 
> 0, align 4
> +  br label %bb2
> +
> +bb2:                                              ; preds = %bb1, %bb
> +  %5 = load %struct.objc_selector** %iftmp.0, align 4 ; < 
> %struct.objc_selector*> [#uses=1]
> +  store %struct.objc_selector* %5, %struct.objc_selector** %sel,  
> align 4
> +  br label %return
> +
> +return:                                           ; preds = %bb2
> +  ret void
> +
> +; CHECK:      __cmd:
> +; CHECK-NEXT: .space 1
> +}
>
>
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