Code gen for x86_64 broken, example included

[llvmbot]

Bugzilla Link	2533
Resolution	FIXED
Resolved on	Mar 06, 2010 13:59
Version	unspecified
OS	Linux
Reporter	LLVM Bugzilla Contributor
CC	@asl

Extended Description

#include <stdio.h>
#include <inttypes.h>

void dummy(const char* a) {}

typedef struct {
const char *name;
int flags;
union {
void (*func_arg)(const char *); //FIXME passing error code as int return would be nicer then exit() in the func
} u;
} OptionDef;

const OptionDef options[] = {
/* main options */
{ "a", 0, {dummy} },
{ "b", 0, {dummy} },
{ 0, },
};

int main(int argc, char *argv)
{
const OptionDef po;
for (po=options; po->name!=0; po++) {
printf("%s\n", po->name);
}
return 0;
}

This code should iterate over all elements in 'options'. The code generated with llvm-gcc (2.3 stable) however, does not do this. When compiled with gcc, everything works as expected. On x86_32, llvm-gcc generates correct code.

[llvmbot]

The initializer for "options" thinks there is padding between elements; the code doesn't. Code is right. I'll take care of this.

[llvmbot]

The immediate cause is patch 50317. Backing that out fixes this and does not break any compatibility tests in the gcc testsuite on Darwin x86-32 or x86-64. I'd be a lot happier if we knew why that patch went in, though, trying to figure it out....

[llvmbot]

Devang says it was a testsuite issue, and if that still works we don't need the patch any more. Gone.
http://llvm.org/viewvc/llvm-project?view=rev&revision=53338