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authorAlan Modra <amodra@gmail.com>2013-08-17 18:41:17 +0930
committerAlan Modra <amodra@gmail.com>2013-10-04 10:39:52 +0930
commit8a7413f9b036da83ffde491a37d9d2340bc321a7 (patch)
tree8ba04b78fde9893b9da3a10e7934a2c127594f6e /sysdeps/powerpc/powerpc64/power4
parentPowerPC LE strnlen (diff)
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PowerPC LE strcmp and strncmp
http://sourceware.org/ml/libc-alpha/2013-08/msg00099.html More little-endian support. I leave the main strcmp loops unchanged, (well, except for renumbering rTMP to something other than r0 since it's needed in an addi insn) and modify the tail for little-endian. I noticed some of the big-endian tail code was a little untidy so have cleaned that up too. * sysdeps/powerpc/powerpc64/strcmp.S (rTMP2): Define as r0. (rTMP): Define as r11. (strcmp): Add little-endian support. Optimise tail. * sysdeps/powerpc/powerpc32/strcmp.S: Similarly. * sysdeps/powerpc/powerpc64/strncmp.S: Likewise. * sysdeps/powerpc/powerpc32/strncmp.S: Likewise. * sysdeps/powerpc/powerpc64/power4/strncmp.S: Likewise. * sysdeps/powerpc/powerpc32/power4/strncmp.S: Likewise. * sysdeps/powerpc/powerpc64/power7/strncmp.S: Likewise. * sysdeps/powerpc/powerpc32/power7/strncmp.S: Likewise.
Diffstat (limited to 'sysdeps/powerpc/powerpc64/power4')
-rw-r--r--sysdeps/powerpc/powerpc64/power4/strncmp.S63
1 files changed, 55 insertions, 8 deletions
diff --git a/sysdeps/powerpc/powerpc64/power4/strncmp.S b/sysdeps/powerpc/powerpc64/power4/strncmp.S
index 1276e16a59..5d136cfa21 100644
--- a/sysdeps/powerpc/powerpc64/power4/strncmp.S
+++ b/sysdeps/powerpc/powerpc64/power4/strncmp.S
@@ -25,7 +25,7 @@
EALIGN (strncmp, 4, 0)
CALL_MCOUNT 3
-#define rTMP r0
+#define rTMP2 r0
#define rRTN r3
#define rSTR1 r3 /* first string arg */
#define rSTR2 r4 /* second string arg */
@@ -38,6 +38,7 @@ EALIGN (strncmp, 4, 0)
#define r7F7F r9 /* constant 0x7f7f7f7f7f7f7f7f */
#define rNEG r10 /* ~(word in s1 | 0x7f7f7f7f7f7f7f7f) */
#define rBITDIF r11 /* bits that differ in s1 & s2 words */
+#define rTMP r12
dcbt 0,rSTR1
or rTMP, rSTR2, rSTR1
@@ -79,12 +80,59 @@ L(g1): add rTMP, rFEFE, rWORD1
we don't compare two strings as different because of gunk beyond
the end of the strings... */
+#ifdef __LITTLE_ENDIAN__
+L(endstring):
+ addi rTMP2, rTMP, -1
+ beq cr1, L(equal)
+ andc rTMP2, rTMP2, rTMP
+ rldimi rTMP2, rTMP2, 1, 0
+ and rWORD2, rWORD2, rTMP2 /* Mask off gunk. */
+ and rWORD1, rWORD1, rTMP2
+ cmpd cr1, rWORD1, rWORD2
+ beq cr1, L(equal)
+ xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */
+ neg rNEG, rBITDIF
+ and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */
+ cntlzd rNEG, rNEG /* bitcount of the bit. */
+ andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */
+ sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */
+ sld rWORD2, rWORD2, rNEG
+ xor. rBITDIF, rWORD1, rWORD2
+ sub rRTN, rWORD1, rWORD2
+ blt- L(highbit)
+ sradi rRTN, rRTN, 63 /* must return an int. */
+ ori rRTN, rRTN, 1
+ blr
+L(equal):
+ li rRTN, 0
+ blr
+
+L(different):
+ ld rWORD1, -8(rSTR1)
+ xor rBITDIF, rWORD1, rWORD2 /* rBITDIF has bits that differ. */
+ neg rNEG, rBITDIF
+ and rNEG, rNEG, rBITDIF /* rNEG has LS bit that differs. */
+ cntlzd rNEG, rNEG /* bitcount of the bit. */
+ andi. rNEG, rNEG, 56 /* bitcount to LS byte that differs. */
+ sld rWORD1, rWORD1, rNEG /* shift left to clear MS bytes. */
+ sld rWORD2, rWORD2, rNEG
+ xor. rBITDIF, rWORD1, rWORD2
+ sub rRTN, rWORD1, rWORD2
+ blt- L(highbit)
+ sradi rRTN, rRTN, 63
+ ori rRTN, rRTN, 1
+ blr
+L(highbit):
+ sradi rRTN, rWORD2, 63
+ ori rRTN, rRTN, 1
+ blr
+
+#else
L(endstring):
and rTMP, r7F7F, rWORD1
beq cr1, L(equal)
add rTMP, rTMP, r7F7F
xor. rBITDIF, rWORD1, rWORD2
-
andc rNEG, rNEG, rTMP
blt- L(highbit)
cntlzd rBITDIF, rBITDIF
@@ -93,7 +141,7 @@ L(endstring):
cmpd cr1, rNEG, rBITDIF
sub rRTN, rWORD1, rWORD2
blt- cr1, L(equal)
- sradi rRTN, rRTN, 63
+ sradi rRTN, rRTN, 63 /* must return an int. */
ori rRTN, rRTN, 1
blr
L(equal):
@@ -101,7 +149,7 @@ L(equal):
blr
L(different):
- ldu rWORD1, -8(rSTR1)
+ ld rWORD1, -8(rSTR1)
xor. rBITDIF, rWORD1, rWORD2
sub rRTN, rWORD1, rWORD2
blt- L(highbit)
@@ -109,11 +157,10 @@ L(different):
ori rRTN, rRTN, 1
blr
L(highbit):
- srdi rWORD2, rWORD2, 56
- srdi rWORD1, rWORD1, 56
- sub rRTN, rWORD1, rWORD2
+ sradi rRTN, rWORD2, 63
+ ori rRTN, rRTN, 1
blr
-
+#endif
/* Oh well. In this case, we just do a byte-by-byte comparison. */
.align 4