glibc/sysdeps/powerpc/ifunc-sel.h
Joseph Myers 4dc23804a2 Fix powerpc ifunc-sel.h build for -Os.
Compiling the testsuite for powerpc (multi-arch configurations) with
-Os with GCC 7 fails with:

In file included from ifuncmod1.c:7:0,
                 from ifuncdep1.c:3:
../sysdeps/powerpc/ifunc-sel.h: In function 'ifunc_sel':
../sysdeps/powerpc/ifunc-sel.h:12:3: error: asm operand 2 probably doesn't match constraints [-Werror]
   __asm__ ("mflr 12\n\t"
   ^~~~~~~
../sysdeps/powerpc/ifunc-sel.h:12:3: error: asm operand 3 probably doesn't match constraints [-Werror]
../sysdeps/powerpc/ifunc-sel.h:12:3: error: asm operand 4 probably doesn't match constraints [-Werror]
../sysdeps/powerpc/ifunc-sel.h:12:3: error: impossible constraint in 'asm'

The "i" constraints on function pointers require the function call to
be inlined so the compiler can see the constant function pointer
arguments passed to the asm.  This patch marks the relevant functions
as always_inline accordingly.

Tested that this fixes the -Os testsuite build for
powerpc-linux-gnu-power4, powerpc64-linux-gnu, powerpc64le-linux-gnu
with build-many-glibcs.py.

	* sysdeps/powerpc/ifunc-sel.h (ifunc_sel): Make always_inline.
	(ifunc_one): Likewise.
2018-03-02 22:27:56 +00:00

52 lines
1.1 KiB
C

/* Used by the elf ifunc tests. */
#ifndef ELF_IFUNC_SEL_H
#define ELF_IFUNC_SEL_H 1
extern int global;
static inline __attribute__ ((always_inline)) void *
inhibit_stack_protector
ifunc_sel (int (*f1) (void), int (*f2) (void), int (*f3) (void))
{
register void *ret __asm__ ("r3");
__asm__ ("mflr 12\n\t"
"bcl 20,31,1f\n"
"1:\tmflr 11\n\t"
"mtlr 12\n\t"
"addis 12,11,global-1b@ha\n\t"
"lwz 12,global-1b@l(12)\n\t"
"addis %0,11,%2-1b@ha\n\t"
"addi %0,%0,%2-1b@l\n\t"
"cmpwi 12,1\n\t"
"beq 2f\n\t"
"addis %0,11,%3-1b@ha\n\t"
"addi %0,%0,%3-1b@l\n\t"
"cmpwi 12,-1\n\t"
"beq 2f\n\t"
"addis %0,11,%4-1b@ha\n\t"
"addi %0,%0,%4-1b@l\n\t"
"2:"
: "=r" (ret)
: "i" (&global), "i" (f1), "i" (f2), "i" (f3)
: "11", "12", "cr0");
return ret;
}
static inline __attribute__ ((always_inline)) void *
inhibit_stack_protector
ifunc_one (int (*f1) (void))
{
register void *ret __asm__ ("r3");
__asm__ ("mflr 12\n\t"
"bcl 20,31,1f\n"
"1:\tmflr %0\n\t"
"mtlr 12\n\t"
"addis %0,%0,%1-1b@ha\n\t"
"addi %0,%0,%1-1b@l"
: "=r" (ret)
: "i" (f1)
: "12");
return ret;
}
#endif