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authorAnton Blanchard <anton@au1.ibm.com>2013-08-17 18:34:40 +0930
committerAlan Modra <amodra@gmail.com>2013-10-04 10:37:59 +0930
commitbe1e5d311342e08ae1f8013342df27b7ded2c156 (patch)
treeccf1ca254c3aa1392262c72de0b960eb1ec7ec21 /sysdeps/powerpc/jmpbuf-offsets.h
parentfef13a78ea30d4c26d6bab48d731ebe864ee31b0 (diff)
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PowerPC LE setjmp/longjmp
http://sourceware.org/ml/libc-alpha/2013-08/msg00089.html

Little-endian fixes for setjmp/longjmp.  When writing these I noticed
the setjmp code corrupts the non volatile VMX registers when using an
unaligned buffer.  Anton fixed this, and also simplified it quite a
bit.

The current code uses boilerplate for the case where we want to store
16 bytes to an unaligned address.  For that we have to do a
read/modify/write of two aligned 16 byte quantities.  In our case we
are storing a bunch of back to back data (consective VMX registers),
and only the start and end of the region need the read/modify/write.

	[BZ #15723]
	* sysdeps/powerpc/jmpbuf-offsets.h: Comment fix.
	* sysdeps/powerpc/powerpc32/fpu/__longjmp-common.S: Correct
	_dl_hwcap access for little-endian.
	* sysdeps/powerpc/powerpc32/fpu/setjmp-common.S: Likewise.  Don't
	destroy vmx regs when saving unaligned.
	* sysdeps/powerpc/powerpc64/__longjmp-common.S: Correct CR load.
	* sysdeps/powerpc/powerpc64/setjmp-common.S: Likewise CR save.  Don't
	destroy vmx regs when saving unaligned.
Diffstat (limited to 'sysdeps/powerpc/jmpbuf-offsets.h')
-rw-r--r--sysdeps/powerpc/jmpbuf-offsets.h6
1 files changed, 2 insertions, 4 deletions
diff --git a/sysdeps/powerpc/jmpbuf-offsets.h b/sysdeps/powerpc/jmpbuf-offsets.h
index 64c658a588..f2116bd703 100644
--- a/sysdeps/powerpc/jmpbuf-offsets.h
+++ b/sysdeps/powerpc/jmpbuf-offsets.h
@@ -21,12 +21,10 @@
 #define JB_LR     2  /* The address we will return to */
 #if __WORDSIZE == 64
 # define JB_GPRS   3  /* GPRs 14 through 31 are saved, 18*2 words total.  */
-# define JB_CR     21 /* Condition code registers with the VRSAVE at */
-                       /* offset 172 (low half of the double word.  */
+# define JB_CR     21 /* Shared dword with VRSAVE.  CR word at offset 172.  */
 # define JB_FPRS   22 /* FPRs 14 through 31 are saved, 18*2 words total.  */
 # define JB_SIZE   (64 * 8) /* As per PPC64-VMX ABI.  */
-# define JB_VRSAVE 21 /* VRSAVE shares a double word with the CR at offset */
-                       /* 168 (high half of the double word).  */
+# define JB_VRSAVE 21 /* Shared dword with CR.  VRSAVE word at offset 168.  */
 # define JB_VRS    40 /* VRs 20 through 31 are saved, 12*4 words total.  */
 #else
 # define JB_GPRS   3  /* GPRs 14 through 31 are saved, 18 in total.  */