rs6000 stack boundary

[Alan Modra]

Fixes some problems with STACK_BOUNDARY.  Altivec needs 16 byte
alignment whether or no -mabi=altivec is given, and PowerPC64 Linux
always has a 16 byte aligned stack.  On PowerPC64 Linux, the sysv4.h
definition unfortunately overrode the rs6000.h one.

	* config/rs6000/rs6000.h (STACK_BOUNDARY): Use 128 bit for either
	TARGET_ALTIVEC or TARGET_ALTIVEC_ABI.
	* config/rs6000/sysv4.h (ABI_STACK_BOUNDARY): Likewise.
	(STACK_BOUNDARY): Delete.

Regression tested powerpc64-linux.  OK for mainline?

Index: gcc/config/rs6000/rs6000.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/rs6000.h,v
retrieving revision 1.320
diff -u -p -r1.320 rs6000.h
--- gcc/config/rs6000/rs6000.h	24 Apr 2004 06:37:19 -0000	1.320
+++ gcc/config/rs6000/rs6000.h	30 Apr 2004 14:29:35 -0000
@@ -718,7 +718,8 @@ extern const char *rs6000_warn_altivec_l
 #define PARM_BOUNDARY (TARGET_32BIT ? 32 : 64)
 
 /* Boundary (in *bits*) on which stack pointer should be aligned.  */
-#define STACK_BOUNDARY ((TARGET_32BIT && !TARGET_ALTIVEC_ABI) ? 64 : 128)
+#define STACK_BOUNDARY \
+  ((TARGET_32BIT && !TARGET_ALTIVEC && !TARGET_ALTIVEC_ABI) ? 64 : 128)
 
 /* Allocation boundary (in *bits*) for the code of a function.  */
 #define FUNCTION_BOUNDARY 32
Index: gcc/config/rs6000/sysv4.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/rs6000/sysv4.h,v
retrieving revision 1.148
diff -u -p -r1.148 sysv4.h
--- gcc/config/rs6000/sysv4.h	11 Apr 2004 06:21:05 -0000	1.148
+++ gcc/config/rs6000/sysv4.h	30 Apr 2004 14:29:36 -0000
@@ -385,12 +385,6 @@ do {									\
 #undef	STRICT_ALIGNMENT
 #define	STRICT_ALIGNMENT (TARGET_STRICT_ALIGN)
 
-/* Alignment in bits of the stack boundary.  Note, in order to allow building
-   one set of libraries with -mno-eabi instead of eabi libraries and non-eabi
-   versions, just use 64 as the stack boundary.  */
-#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
@@ -407,7 +401,8 @@ do {									\
 #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)
+#define ABI_STACK_BOUNDARY \
+  ((TARGET_EABI && !TARGET_ALTIVEC && !TARGET_ALTIVEC_ABI) ? 64 : 128)
 
 /* An expression for the alignment of a structure field FIELD if the
    alignment computed in the usual way is COMPUTED.  */

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre