increase some Xtensa stack frame sizes

[Bob Wilson <bwilson at tensilica dot com>]

This patch fixes up the stack frame sizes for some Xtensa assembly functions.  
There are two unrelated reasons for this.  First, the _init and _fini 
functions were using a frame size with insufficient alignment.  The patch 
also adds some extra stack space for these functions in case any of the _init 
or _fini code ever needs extra scratch space.  Second, some future Xtensa 
configurations may only support a fixed register window size of 8, and this 
will require leaf functions to include a 4-word "extra save area" even though 
they would not otherwise need that space.  The patch increases the frame size 
for all the lib1funcs.asm functions to 32 to leave room for this extra save 
area.  Committed on mainline.

2003-07-23  Bob Wilson  <bob.wilson@acm.org>

        * config/xtensa/crti.asm (_init, _fini): Increase frame size to 64.
        * config/xtensa/lib1funcs.asm (__mulsi3, __udivsi3, __divsi3,
        __umodsi3, __modsi3): Increase frame size to 32.

Index: crti.asm
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/xtensa/crti.asm,v
retrieving revision 1.1
diff -u -p -r1.1 crti.asm
--- crti.asm	24 Jan 2003 21:51:03 -0000	1.1
+++ crti.asm	23 Jul 2003 19:48:59 -0000
@@ -34,11 +34,11 @@
 	.type _init,@function
 	.align	4
 _init:
-	entry	sp, 40
+	entry	sp, 64
 
 	.section .fini
 	.globl _fini
 	.type _fini,@function
 	.align	4
 _fini:
-	entry	sp, 40
+	entry	sp, 64
Index: lib1funcs.asm
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/xtensa/lib1funcs.asm,v
retrieving revision 1.4
diff -u -p -r1.4 lib1funcs.asm
--- lib1funcs.asm	1 Jul 2003 00:14:30 -0000	1.4
+++ lib1funcs.asm	23 Jul 2003 19:48:59 -0000
@@ -30,8 +30,13 @@ Software Foundation, 59 Temple Place - S
 
 #include "xtensa-config.h"
 
-	# Define macros for the ABS and ADDX* instructions to handle cases
-	# where they are not included in the Xtensa processor configuration.
+# Note: These functions use a minimum stack frame size of 32.  This is
+# necessary for Xtensa configurations that only support a fixed register
+# window size of 8, where even leaf functions (such as these) need to
+# allocate space for a 4-word "extra save area".
+
+# Define macros for the ABS and ADDX* instructions to handle cases
+# where they are not included in the Xtensa processor configuration.
 
 	.macro	do_abs dst, src, tmp
 #if XCHAL_HAVE_ABS
@@ -75,7 +80,7 @@ Software Foundation, 59 Temple Place - S
 	.global	__mulsi3
 	.type	__mulsi3,@function
 __mulsi3:
-	entry	sp, 16
+	entry	sp, 32
 
 #if XCHAL_HAVE_MUL16
 	or	a4, a2, a3
@@ -174,11 +179,11 @@ __mulsi3:
 #endif /* L_mulsi3 */
 
 
-	# Define a macro for the NSAU (unsigned normalize shift amount)
-	# instruction, which computes the number of leading zero bits,
-	# to handle cases where it is not included in the Xtensa processor
-	# configuration.
-	
+# Define a macro for the NSAU (unsigned normalize shift amount)
+# instruction, which computes the number of leading zero bits,
+# to handle cases where it is not included in the Xtensa processor
+# configuration.
+
 	.macro	do_nsau cnt, val, tmp, a
 #if XCHAL_HAVE_NSA
 	nsau	\cnt, \val
@@ -237,7 +242,7 @@ __nsau_data:	
 	.global	__udivsi3
 	.type	__udivsi3,@function
 __udivsi3:
-	entry	sp, 16
+	entry	sp, 32
 	bltui	a3, 2, .Lle_one	# check if the divisor <= 1
 
 	mov	a6, a2		# keep dividend in a6
@@ -296,7 +301,7 @@ __udivsi3:
 	.global	__divsi3
 	.type	__divsi3,@function
 __divsi3:
-	entry	sp, 16
+	entry	sp, 32
 	xor	a7, a2, a3	# sign = dividend ^ divisor
 	do_abs	a6, a2, a4	# udividend = abs(dividend)
 	do_abs	a3, a3, a4	# udivisor = abs(divisor)
@@ -361,7 +366,7 @@ __divsi3:
 	.global	__umodsi3
 	.type	__umodsi3,@function
 __umodsi3:
-	entry	sp, 16
+	entry	sp, 32
 	bltui	a3, 2, .Lle_one	# check if the divisor is <= 1
 
 	do_nsau	a5, a2, a6, a7	# dividend_shift = nsau(dividend)
@@ -413,7 +418,7 @@ __umodsi3:
 	.global	__modsi3
 	.type	__modsi3,@function
 __modsi3:
-	entry	sp, 16
+	entry	sp, 32
 	mov	a7, a2		# save original (signed) dividend
 	do_abs	a2, a2, a4	# udividend = abs(dividend)
 	do_abs	a3, a3, a4	# udivisor = abs(divisor)