# commit 664318c3eb07032e2bfcf47cb2aa3c89280c19e7
# Author: Alan Modra <amodra@gmail.com>
# Date: Sat Aug 17 18:46:05 2013 +0930
#
# PowerPC LE strchr
# http://sourceware.org/ml/libc-alpha/2013-08/msg00101.html
#
# Adds little-endian support to optimised strchr assembly. I've also
# tweaked the big-endian code a little. In power7/strchr.S there's a
# check in the tail of the function that we didn't match 0 before
# finding a c match, done by comparing leading zero counts. It's just
# as valid, and quicker, to compare the raw output from cmpb.
#
# Another little tweak is to use rldimi/insrdi in place of rlwimi for
# the power7 strchr functions. Since rlwimi is cracked, it is a few
# cycles slower. rldimi can be used on the 32-bit power7 functions
# too.
#
# * sysdeps/powerpc/powerpc64/power7/strchr.S (strchr): Add little-endian
# support. Correct typos, formatting. Optimize tail. Use insrdi
# rather than rlwimi.
# * sysdeps/powerpc/powerpc32/power7/strchr.S: Likewise.
# * sysdeps/powerpc/powerpc64/power7/strchrnul.S (__strchrnul): Add
# little-endian support. Correct typos.
# * sysdeps/powerpc/powerpc32/power7/strchrnul.S: Likewise. Use insrdi
# rather than rlwimi.
# * sysdeps/powerpc/powerpc64/strchr.S (rTMP4, rTMP5): Define. Use
# in loop and entry code to keep "and." results.
# (strchr): Add little-endian support. Comment. Move cntlzd
# earlier in tail.
# * sysdeps/powerpc/powerpc32/strchr.S: Likewise.
#
Index: glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/power7/strchr.S
===================================================================
--- glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/power7/strchr.S.orig
+++ glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/power7/strchr.S
@@ -37,8 +37,8 @@ ENTRY (BP_SYM(strchr))
beq cr7,L(null_match)
/* Replicate byte to word. */
- rlwimi r4,r4,8,16,23
- rlwimi r4,r4,16,0,15
+ insrdi r4,r4,8,48
+ insrdi r4,r4,16,32
/* Now r4 has a word of c bytes and r0 has
a word of null bytes. */
@@ -48,11 +48,17 @@ ENTRY (BP_SYM(strchr))
/* Move the words left and right to discard the bits that are
not part of the string and to bring them back as zeros. */
-
+#ifdef __LITTLE_ENDIAN__
+ srw r10,r10,r6
+ srw r11,r11,r6
+ slw r10,r10,r6
+ slw r11,r11,r6
+#else
slw r10,r10,r6
slw r11,r11,r6
srw r10,r10,r6
srw r11,r11,r6
+#endif
or r5,r10,r11 /* OR the results to speed things up. */
cmpwi cr7,r5,0 /* If r5 == 0, no c or null bytes
have been found. */
@@ -67,7 +73,7 @@ ENTRY (BP_SYM(strchr))
/* Handle WORD2 of pair. */
lwzu r12,4(r8)
- cmpb r10,r12,r4
+ cmpb r10,r12,r4
cmpb r11,r12,r0
or r5,r10,r11
cmpwi cr7,r5,0
@@ -102,22 +108,31 @@ L(loop):
bne cr6,L(done)
/* The c/null byte must be in the second word. Adjust the address
- again and move the result of cmpb to r10 so we can calculate the
- pointer. */
+ again and move the result of cmpb to r10/r11 so we can calculate
+ the pointer. */
mr r10,r6
mr r11,r7
addi r8,r8,4
- /* r5 has the output of the cmpb instruction, that is, it contains
+ /* r10/r11 have the output of the cmpb instructions, that is,
0xff in the same position as the c/null byte in the original
word from the string. Use that to calculate the pointer. */
L(done):
- cntlzw r4,r10 /* Count leading zeroes before c matches. */
- cntlzw r0,r11 /* Count leading zeroes before null matches. */
- cmplw cr7,r4,r0
+#ifdef __LITTLE_ENDIAN__
+ addi r3,r10,-1
+ andc r3,r3,r10
+ popcntw r0,r3
+ addi r4,r11,-1
+ andc r4,r4,r11
+ cmplw cr7,r3,r4
+ bgt cr7,L(no_match)
+#else
+ cntlzw r0,r10 /* Count leading zeros before c matches. */
+ cmplw cr7,r11,r10
bgt cr7,L(no_match)
- srwi r0,r4,3 /* Convert leading zeroes to bytes. */
+#endif
+ srwi r0,r0,3 /* Convert leading zeros to bytes. */
add r3,r8,r0 /* Return address of the matching c byte
or null in case c was not found. */
blr
@@ -135,10 +150,14 @@ L(null_match):
cmpb r5,r12,r0 /* Compare each byte against null bytes. */
/* Move the words left and right to discard the bits that are
- not part of the string and to bring them back as zeros. */
-
+ not part of the string and bring them back as zeros. */
+#ifdef __LITTLE_ENDIAN__
+ srw r5,r5,r6
+ slw r5,r5,r6
+#else
slw r5,r5,r6
srw r5,r5,r6
+#endif
cmpwi cr7,r5,0 /* If r10 == 0, no c or null bytes
have been found. */
bne cr7,L(done_null)
@@ -193,7 +212,13 @@ L(loop_null):
0xff in the same position as the null byte in the original
word from the string. Use that to calculate the pointer. */
L(done_null):
+#ifdef __LITTLE_ENDIAN__
+ addi r0,r5,-1
+ andc r0,r0,r5
+ popcntw r0,r0
+#else
cntlzw r0,r5 /* Count leading zeros before the match. */
+#endif
srwi r0,r0,3 /* Convert leading zeros to bytes. */
add r3,r8,r0 /* Return address of the matching null byte. */
blr
Index: glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/power7/strchrnul.S
===================================================================
--- glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/power7/strchrnul.S.orig
+++ glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/power7/strchrnul.S
@@ -29,8 +29,8 @@ ENTRY (BP_SYM(__strchrnul))
clrrwi r8,r3,2 /* Align the address to word boundary. */
/* Replicate byte to word. */
- rlwimi r4,r4,8,16,23
- rlwimi r4,r4,16,0,15
+ insrdi r4,r4,8,48
+ insrdi r4,r4,16,32
rlwinm r6,r3,3,27,28 /* Calculate padding. */
lwz r12,0(r8) /* Load word from memory. */
@@ -45,10 +45,17 @@ ENTRY (BP_SYM(__strchrnul))
/* Move the words left and right to discard the bits that are
not part of the string and bring them back as zeros. */
+#ifdef __LITTLE_ENDIAN__
+ srw r10,r10,r6
+ srw r9,r9,r6
+ slw r10,r10,r6
+ slw r9,r9,r6
+#else
slw r10,r10,r6
slw r9,r9,r6
srw r10,r10,r6
srw r9,r9,r6
+#endif
or r5,r9,r10 /* OR the results to speed things up. */
cmpwi cr7,r5,0 /* If r5 == 0, no c or null bytes
have been found. */
@@ -56,7 +63,7 @@ ENTRY (BP_SYM(__strchrnul))
mtcrf 0x01,r8
- /* Are we now aligned to a quadword boundary? If so, skip to
+ /* Are we now aligned to a doubleword boundary? If so, skip to
the main loop. Otherwise, go through the alignment code. */
bt 29,L(loop)
@@ -78,7 +85,7 @@ L(loop):
single register for speed. This is an attempt
to speed up the null-checking process for bigger strings. */
lwz r12,4(r8)
- lwzu r11,8(r8)
+ lwzu r11,8(r8)
cmpb r10,r12,r0
cmpb r9,r12,r4
cmpb r6,r11,r0
@@ -97,9 +104,9 @@ L(loop):
addi r8,r8,-4
bne cr6,L(done)
- /* The c/null byte must be in the second word. Adjust the
- address again and move the result of cmpb to r10 so we can calculate
- the pointer. */
+ /* The c/null byte must be in the second word. Adjust the address
+ again and move the result of cmpb to r5 so we can calculate the
+ pointer. */
mr r5,r10
addi r8,r8,4
@@ -107,7 +114,13 @@ L(loop):
0xff in the same position as the c/null byte in the original
word from the string. Use that to calculate the pointer. */
L(done):
+#ifdef __LITTLE_ENDIAN__
+ addi r0,r5,-1
+ andc r0,r0,r5
+ popcntw r0,r0
+#else
cntlzw r0,r5 /* Count leading zeros before the match. */
+#endif
srwi r0,r0,3 /* Convert leading zeros to bytes. */
add r3,r8,r0 /* Return address of matching c/null byte. */
blr
Index: glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/strchr.S
===================================================================
--- glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/strchr.S.orig
+++ glibc-2.17-c758a686/sysdeps/powerpc/powerpc32/strchr.S
@@ -44,6 +44,8 @@ ENTRY (BP_SYM (strchr))
#define rIGN r10 /* number of bits we should ignore in the first word */
#define rMASK r11 /* mask with the bits to ignore set to 0 */
#define rTMP3 r12
+#define rTMP4 rIGN
+#define rTMP5 rMASK
CHECK_BOUNDS_LOW (rSTR, rTMP1, rTMP2)
STORE_RETURN_BOUNDS (rTMP1, rTMP2)
@@ -59,53 +61,74 @@ ENTRY (BP_SYM (strchr))
addi r7F7F, r7F7F, 0x7f7f
/* Test the first (partial?) word. */
lwz rWORD, 0(rSTR)
+#ifdef __LITTLE_ENDIAN__
+ slw rMASK, rMASK, rIGN
+#else
srw rMASK, rMASK, rIGN
+#endif
orc rWORD, rWORD, rMASK
add rTMP1, rFEFE, rWORD
nor rTMP2, r7F7F, rWORD
- and. rTMP1, rTMP1, rTMP2
+ and. rTMP4, rTMP1, rTMP2
xor rTMP3, rCHR, rWORD
orc rTMP3, rTMP3, rMASK
b L(loopentry)
/* The loop. */
-L(loop):lwzu rWORD, 4(rSTR)
- and. rTMP1, rTMP1, rTMP2
+L(loop):
+ lwzu rWORD, 4(rSTR)
+ and. rTMP5, rTMP1, rTMP2
/* Test for 0. */
- add rTMP1, rFEFE, rWORD
- nor rTMP2, r7F7F, rWORD
+ add rTMP1, rFEFE, rWORD /* x - 0x01010101. */
+ nor rTMP2, r7F7F, rWORD /* ~(x | 0x7f7f7f7f) == ~x & 0x80808080. */
bne L(foundit)
- and. rTMP1, rTMP1, rTMP2
+ and. rTMP4, rTMP1, rTMP2 /* (x - 0x01010101) & ~x & 0x80808080. */
/* Start test for the bytes we're looking for. */
xor rTMP3, rCHR, rWORD
L(loopentry):
add rTMP1, rFEFE, rTMP3
nor rTMP2, r7F7F, rTMP3
beq L(loop)
+
/* There is a zero byte in the word, but may also be a matching byte (either
before or after the zero byte). In fact, we may be looking for a
- zero byte, in which case we return a match. We guess that this hasn't
- happened, though. */
-L(missed):
- and. rTMP1, rTMP1, rTMP2
+ zero byte, in which case we return a match. */
+ and. rTMP5, rTMP1, rTMP2
li rRTN, 0
STORE_RETURN_VALUE (rSTR)
beqlr
-/* It did happen. Decide which one was first...
- I'm not sure if this is actually faster than a sequence of
- rotates, compares, and branches (we use it anyway because it's shorter). */
+/* At this point:
+ rTMP5 bytes are 0x80 for each match of c, 0 otherwise.
+ rTMP4 bytes are 0x80 for each match of 0, 0 otherwise.
+ But there may be false matches in the next most significant byte from
+ a true match due to carries. This means we need to recalculate the
+ matches using a longer method for big-endian. */
+#ifdef __LITTLE_ENDIAN__
+ addi rTMP1, rTMP5, -1
+ andc rTMP1, rTMP1, rTMP5
+ cntlzw rCLZB, rTMP1
+ addi rTMP2, rTMP4, -1
+ andc rTMP2, rTMP2, rTMP4
+ cmplw rTMP1, rTMP2
+ bgtlr
+ subfic rCLZB, rCLZB, 32-7
+#else
+/* I think we could reduce this by two instructions by keeping the "nor"
+ results from the loop for reuse here. See strlen.S tail. Similarly
+ one instruction could be pruned from L(foundit). */
and rFEFE, r7F7F, rWORD
- or rMASK, r7F7F, rWORD
+ or rTMP5, r7F7F, rWORD
and rTMP1, r7F7F, rTMP3
- or rIGN, r7F7F, rTMP3
+ or rTMP4, r7F7F, rTMP3
add rFEFE, rFEFE, r7F7F
add rTMP1, rTMP1, r7F7F
- nor rWORD, rMASK, rFEFE
- nor rTMP2, rIGN, rTMP1
+ nor rWORD, rTMP5, rFEFE
+ nor rTMP2, rTMP4, rTMP1
+ cntlzw rCLZB, rTMP2
cmplw rWORD, rTMP2
bgtlr
- cntlzw rCLZB, rTMP2
+#endif
srwi rCLZB, rCLZB, 3
add rRTN, rSTR, rCLZB
CHECK_BOUNDS_HIGH_RTN (rSTR, rTMP2, twlge)
@@ -113,13 +136,21 @@ L(missed):
blr
L(foundit):
+#ifdef __LITTLE_ENDIAN__
+ addi rTMP1, rTMP5, -1
+ andc rTMP1, rTMP1, rTMP5
+ cntlzw rCLZB, rTMP1
+ subfic rCLZB, rCLZB, 32-7-32
+ srawi rCLZB, rCLZB, 3
+#else
and rTMP1, r7F7F, rTMP3
- or rIGN, r7F7F, rTMP3
+ or rTMP4, r7F7F, rTMP3
add rTMP1, rTMP1, r7F7F
- nor rTMP2, rIGN, rTMP1
+ nor rTMP2, rTMP4, rTMP1
cntlzw rCLZB, rTMP2
subi rSTR, rSTR, 4
srwi rCLZB, rCLZB, 3
+#endif
add rRTN, rSTR, rCLZB
CHECK_BOUNDS_HIGH_RTN (rSTR, rTMP2, twlge)
STORE_RETURN_VALUE (rSTR)
Index: glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/power7/strchr.S
===================================================================
--- glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/power7/strchr.S.orig
+++ glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/power7/strchr.S
@@ -37,8 +37,8 @@ ENTRY (BP_SYM(strchr))
beq cr7,L(null_match)
/* Replicate byte to doubleword. */
- rlwimi r4,r4,8,16,23
- rlwimi r4,r4,16,0,15
+ insrdi r4,r4,8,48
+ insrdi r4,r4,16,32
insrdi r4,r4,32,0
/* Now r4 has a doubleword of c bytes and r0 has
@@ -49,11 +49,17 @@ ENTRY (BP_SYM(strchr))
/* Move the doublewords left and right to discard the bits that are
not part of the string and bring them back as zeros. */
-
+#ifdef __LITTLE_ENDIAN__
+ srd r10,r10,r6
+ srd r11,r11,r6
+ sld r10,r10,r6
+ sld r11,r11,r6
+#else
sld r10,r10,r6
sld r11,r11,r6
srd r10,r10,r6
srd r11,r11,r6
+#endif
or r5,r10,r11 /* OR the results to speed things up. */
cmpdi cr7,r5,0 /* If r5 == 0, no c or null bytes
have been found. */
@@ -110,15 +116,24 @@ L(loop):
mr r11,r7
addi r8,r8,8
- /* r5 has the output of the cmpb instruction, that is, it contains
+ /* r10/r11 have the output of the cmpb instructions, that is,
0xff in the same position as the c/null byte in the original
doubleword from the string. Use that to calculate the pointer. */
L(done):
- cntlzd r4,r10 /* Count leading zeroes before c matches. */
- cntlzd r0,r11 /* Count leading zeroes before null matches. */
- cmpld cr7,r4,r0
+#ifdef __LITTLE_ENDIAN__
+ addi r3,r10,-1
+ andc r3,r3,r10
+ popcntd r0,r3
+ addi r4,r11,-1
+ andc r4,r4,r11
+ cmpld cr7,r3,r4
bgt cr7,L(no_match)
- srdi r0,r4,3 /* Convert leading zeroes to bytes. */
+#else
+ cntlzd r0,r10 /* Count leading zeros before c matches. */
+ cmpld cr7,r11,r10
+ bgt cr7,L(no_match)
+#endif
+ srdi r0,r0,3 /* Convert leading zeros to bytes. */
add r3,r8,r0 /* Return address of the matching c byte
or null in case c was not found. */
blr
@@ -137,9 +152,13 @@ L(null_match):
/* Move the doublewords left and right to discard the bits that are
not part of the string and bring them back as zeros. */
-
+#ifdef __LITTLE_ENDIAN__
+ srd r5,r5,r6
+ sld r5,r5,r6
+#else
sld r5,r5,r6
srd r5,r5,r6
+#endif
cmpdi cr7,r5,0 /* If r10 == 0, no c or null bytes
have been found. */
bne cr7,L(done_null)
@@ -194,7 +213,13 @@ L(loop_null):
0xff in the same position as the null byte in the original
doubleword from the string. Use that to calculate the pointer. */
L(done_null):
+#ifdef __LITTLE_ENDIAN__
+ addi r0,r5,-1
+ andc r0,r0,r5
+ popcntd r0,r0
+#else
cntlzd r0,r5 /* Count leading zeros before the match. */
+#endif
srdi r0,r0,3 /* Convert leading zeros to bytes. */
add r3,r8,r0 /* Return address of the matching null byte. */
blr
Index: glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/power7/strchrnul.S
===================================================================
--- glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/power7/strchrnul.S.orig
+++ glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/power7/strchrnul.S
@@ -29,8 +29,8 @@ ENTRY (BP_SYM(__strchrnul))
clrrdi r8,r3,3 /* Align the address to doubleword boundary. */
/* Replicate byte to doubleword. */
- rlwimi r4,r4,8,16,23
- rlwimi r4,r4,16,0,15
+ insrdi r4,r4,8,48
+ insrdi r4,r4,16,32
insrdi r4,r4,32,0
rlwinm r6,r3,3,26,28 /* Calculate padding. */
@@ -46,10 +46,17 @@ ENTRY (BP_SYM(__strchrnul))
/* Move the doublewords left and right to discard the bits that are
not part of the string and to bring them back as zeros. */
+#ifdef __LITTLE_ENDIAN__
+ srd r10,r10,r6
+ srd r9,r9,r6
+ sld r10,r10,r6
+ sld r9,r9,r6
+#else
sld r10,r10,r6
sld r9,r9,r6
srd r10,r10,r6
srd r9,r9,r6
+#endif
or r5,r9,r10 /* OR the results to speed things up. */
cmpdi cr7,r5,0 /* If r5 == 0, no c or null bytes
have been found. */
@@ -99,7 +106,7 @@ L(loop):
bne cr6,L(done)
/* The c/null byte must be in the second doubleword. Adjust the
- address again and move the result of cmpb to r10 so we can calculate
+ address again and move the result of cmpb to r5 so we can calculate
the pointer. */
mr r5,r10
addi r8,r8,8
@@ -108,7 +115,13 @@ L(loop):
0xff in the same position as the c/null byte in the original
doubleword from the string. Use that to calculate the pointer. */
L(done):
+#ifdef __LITTLE_ENDIAN__
+ addi r0,r5,-1
+ andc r0,r0,r5
+ popcntd r0,r0
+#else
cntlzd r0,r5 /* Count leading zeros before the match. */
+#endif
srdi r0,r0,3 /* Convert leading zeros to bytes. */
add r3,r8,r0 /* Return address of matching c/null byte. */
blr
Index: glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/strchr.S
===================================================================
--- glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/strchr.S.orig
+++ glibc-2.17-c758a686/sysdeps/powerpc/powerpc64/strchr.S
@@ -50,14 +50,16 @@ ENTRY (BP_SYM (strchr))
#define rIGN r10 /* number of bits we should ignore in the first word */
#define rMASK r11 /* mask with the bits to ignore set to 0 */
#define rTMP3 r12
+#define rTMP4 rIGN
+#define rTMP5 rMASK
CHECK_BOUNDS_LOW (rSTR, rTMP1, rTMP2)
STORE_RETURN_BOUNDS (rTMP1, rTMP2)
dcbt 0,rRTN
- rlwimi rCHR, rCHR, 8, 16, 23
+ insrdi rCHR, rCHR, 8, 48
li rMASK, -1
- rlwimi rCHR, rCHR, 16, 0, 15
+ insrdi rCHR, rCHR, 16, 32
rlwinm rIGN, rRTN, 3, 26, 28
insrdi rCHR, rCHR, 32, 0
lis rFEFE, -0x101
@@ -70,53 +72,74 @@ ENTRY (BP_SYM (strchr))
add rFEFE, rFEFE, rTMP1
/* Test the first (partial?) word. */
ld rWORD, 0(rSTR)
+#ifdef __LITTLE_ENDIAN__
+ sld rMASK, rMASK, rIGN
+#else
srd rMASK, rMASK, rIGN
+#endif
orc rWORD, rWORD, rMASK
add rTMP1, rFEFE, rWORD
nor rTMP2, r7F7F, rWORD
- and. rTMP1, rTMP1, rTMP2
+ and. rTMP4, rTMP1, rTMP2
xor rTMP3, rCHR, rWORD
orc rTMP3, rTMP3, rMASK
b L(loopentry)
/* The loop. */
-L(loop):ldu rWORD, 8(rSTR)
- and. rTMP1, rTMP1, rTMP2
+L(loop):
+ ldu rWORD, 8(rSTR)
+ and. rTMP5, rTMP1, rTMP2
/* Test for 0. */
- add rTMP1, rFEFE, rWORD
- nor rTMP2, r7F7F, rWORD
+ add rTMP1, rFEFE, rWORD /* x - 0x01010101. */
+ nor rTMP2, r7F7F, rWORD /* ~(x | 0x7f7f7f7f) == ~x & 0x80808080. */
bne L(foundit)
- and. rTMP1, rTMP1, rTMP2
+ and. rTMP4, rTMP1, rTMP2 /* (x - 0x01010101) & ~x & 0x80808080. */
/* Start test for the bytes we're looking for. */
xor rTMP3, rCHR, rWORD
L(loopentry):
add rTMP1, rFEFE, rTMP3
nor rTMP2, r7F7F, rTMP3
beq L(loop)
+
/* There is a zero byte in the word, but may also be a matching byte (either
before or after the zero byte). In fact, we may be looking for a
- zero byte, in which case we return a match. We guess that this hasn't
- happened, though. */
-L(missed):
- and. rTMP1, rTMP1, rTMP2
+ zero byte, in which case we return a match. */
+ and. rTMP5, rTMP1, rTMP2
li rRTN, 0
STORE_RETURN_VALUE (rSTR)
beqlr
-/* It did happen. Decide which one was first...
- I'm not sure if this is actually faster than a sequence of
- rotates, compares, and branches (we use it anyway because it's shorter). */
+/* At this point:
+ rTMP5 bytes are 0x80 for each match of c, 0 otherwise.
+ rTMP4 bytes are 0x80 for each match of 0, 0 otherwise.
+ But there may be false matches in the next most significant byte from
+ a true match due to carries. This means we need to recalculate the
+ matches using a longer method for big-endian. */
+#ifdef __LITTLE_ENDIAN__
+ addi rTMP1, rTMP5, -1
+ andc rTMP1, rTMP1, rTMP5
+ cntlzd rCLZB, rTMP1
+ addi rTMP2, rTMP4, -1
+ andc rTMP2, rTMP2, rTMP4
+ cmpld rTMP1, rTMP2
+ bgtlr
+ subfic rCLZB, rCLZB, 64-7
+#else
+/* I think we could reduce this by two instructions by keeping the "nor"
+ results from the loop for reuse here. See strlen.S tail. Similarly
+ one instruction could be pruned from L(foundit). */
and rFEFE, r7F7F, rWORD
- or rMASK, r7F7F, rWORD
+ or rTMP5, r7F7F, rWORD
and rTMP1, r7F7F, rTMP3
- or rIGN, r7F7F, rTMP3
+ or rTMP4, r7F7F, rTMP3
add rFEFE, rFEFE, r7F7F
add rTMP1, rTMP1, r7F7F
- nor rWORD, rMASK, rFEFE
- nor rTMP2, rIGN, rTMP1
+ nor rWORD, rTMP5, rFEFE
+ nor rTMP2, rTMP4, rTMP1
+ cntlzd rCLZB, rTMP2
cmpld rWORD, rTMP2
bgtlr
- cntlzd rCLZB, rTMP2
+#endif
srdi rCLZB, rCLZB, 3
add rRTN, rSTR, rCLZB
CHECK_BOUNDS_HIGH_RTN (rSTR, rTMP2, tdlge)
@@ -124,13 +147,21 @@ L(missed):
blr
L(foundit):
+#ifdef __LITTLE_ENDIAN__
+ addi rTMP1, rTMP5, -1
+ andc rTMP1, rTMP1, rTMP5
+ cntlzd rCLZB, rTMP1
+ subfic rCLZB, rCLZB, 64-7-64
+ sradi rCLZB, rCLZB, 3
+#else
and rTMP1, r7F7F, rTMP3
- or rIGN, r7F7F, rTMP3
+ or rTMP4, r7F7F, rTMP3
add rTMP1, rTMP1, r7F7F
- nor rTMP2, rIGN, rTMP1
+ nor rTMP2, rTMP4, rTMP1
cntlzd rCLZB, rTMP2
subi rSTR, rSTR, 8
srdi rCLZB, rCLZB, 3
+#endif
add rRTN, rSTR, rCLZB
CHECK_BOUNDS_HIGH_RTN (rSTR, rTMP2, tdlge)
STORE_RETURN_VALUE (rSTR)