diff options
Diffstat (limited to 'contrib/gcc/config/rs6000/sysv4.h')
| -rw-r--r-- | contrib/gcc/config/rs6000/sysv4.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/contrib/gcc/config/rs6000/sysv4.h b/contrib/gcc/config/rs6000/sysv4.h index 3da996fbd54c..26450e7ee273 100644 --- a/contrib/gcc/config/rs6000/sysv4.h +++ b/contrib/gcc/config/rs6000/sysv4.h @@ -383,6 +383,21 @@ do { \ #undef STACK_BOUNDARY #define STACK_BOUNDARY (TARGET_ALTIVEC_ABI ? 128 : 64) +/* Define this macro if you wish to preserve a certain alignment for + the stack pointer, greater than what the hardware enforces. The + definition is a C expression for the desired alignment (measured + in bits). This macro must evaluate to a value equal to or larger + than STACK_BOUNDARY. + For the SYSV ABI and variants the alignment of the stack pointer + is usually controlled manually in rs6000.c. However, to maintain + alignment across alloca () in all circumstances, + PREFERRED_STACK_BOUNDARY needs to be set as well. + This has the additional advantage of allowing a bigger maximum + alignment of user objects on the stack. */ + +#undef PREFERRED_STACK_BOUNDARY +#define PREFERRED_STACK_BOUNDARY 128 + /* Real stack boundary as mandated by the appropriate ABI. */ #define ABI_STACK_BOUNDARY ((TARGET_EABI && !TARGET_ALTIVEC_ABI) ? 64 : 128) |