File: //usr/src/glibc/debian/patches/alpha/local-string-functions.diff
The alpha assembly version of various string functions do not work
correctly on some corner cases, and thus doesn't pass the testsuite.
This patch removes them.
---
sysdeps/alpha/alphaev67/stpncpy.S | 115 -------------
sysdeps/alpha/alphaev67/strncat.S | 87 ----------
sysdeps/alpha/stpncpy.S | 106 ------------
sysdeps/alpha/strcmp.S | 194 ----------------------
sysdeps/alpha/strncat.S | 94 ----------
sysdeps/alpha/strncmp.S | 277 --------------------------------
sysdeps/alpha/strncpy.S | 87 ----------
7 files changed, 960 deletions(-)
--- a/sysdeps/alpha/strncat.S
+++ /dev/null
@@ -1,94 +0,0 @@
-/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Richard Henderson <rth@tamu.edu>, 1996.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <https://www.gnu.org/licenses/>. */
-
-/* Append no more than COUNT characters from the null-terminated string SRC
- to the null-terminated string DST. Always null-terminate the new DST. */
-
-#include <sysdep.h>
-
- .text
-
-ENTRY(strncat)
- ldgp gp, 0(pv)
-#ifdef PROF
- .set noat
- lda AT, _mcount
- jsr AT, (AT), _mcount
- .set at
-#endif
- .prologue 1
-
- mov a0, v0 # set up return value
- beq a2, $zerocount
-
- /* Find the end of the string. */
-
- ldq_u t0, 0(a0) # load first quadword (a0 may be misaligned)
- lda t1, -1(zero)
- insqh t1, a0, t1
- andnot a0, 7, a0
- or t1, t0, t0
- cmpbge zero, t0, t1 # t1 <- bitmask: bit i == 1 <==> i-th byte == 0
- bne t1, $found
-
-$loop: ldq t0, 8(a0)
- addq a0, 8, a0 # addr += 8
- cmpbge zero, t0, t1
- beq t1, $loop
-
-$found: negq t1, t2 # clear all but least set bit
- and t1, t2, t1
-
- and t1, 0xf0, t2 # binary search for that set bit
- and t1, 0xcc, t3
- and t1, 0xaa, t4
- cmovne t2, 4, t2
- cmovne t3, 2, t3
- cmovne t4, 1, t4
- addq t2, t3, t2
- addq a0, t4, a0
- addq a0, t2, a0
-
- /* Now do the append. */
-
- jsr t9, __stxncpy
-
- /* Worry about the null termination. */
-
- zapnot t0, t8, t1 # was last byte a null?
- bne t1, 0f
- ret
-
-0: and t10, 0x80, t1
- bne t1, 1f
-
- /* Here there are bytes left in the current word. Clear one. */
- addq t10, t10, t10 # end-of-count bit <<= 1
- zap t0, t10, t0
- stq_u t0, 0(a0)
- ret
-
-1: /* Here we must read the next DST word and clear the first byte. */
- ldq_u t0, 8(a0)
- zap t0, 1, t0
- stq_u t0, 8(a0)
-
-$zerocount:
- ret
-
- END(strncat)
--- a/sysdeps/alpha/strncpy.S
+++ /dev/null
@@ -1,87 +0,0 @@
-/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
- Contributed by Richard Henderson (rth@tamu.edu)
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <https://www.gnu.org/licenses/>. */
-
-/* Copy no more than COUNT bytes of the null-terminated string from
- SRC to DST. If SRC does not cover all of COUNT, the balance is
- zeroed. */
-
-#include <sysdep.h>
-
- .set noat
- .set noreorder
-
- .text
-
-ENTRY(strncpy)
- ldgp gp, 0(pv)
-#ifdef PROF
- lda AT, _mcount
- jsr AT, (AT), _mcount
-#endif
- .prologue 1
-
- mov a0, v0 # set return value now
- beq a2, $zerocount
- jsr t9, __stxncpy # do the work of the copy
-
- bne a2, $multiword # do we have full words left?
-
- .align 3
- subq t8, 1, t2 # e0 : guess not
- subq t10, 1, t3 # .. e1 :
- or t2, t8, t2 # e0 : clear the bits between the last
- or t3, t10, t3 # .. e1 : written byte and the last byte in
- andnot t3, t2, t3 # e0 : COUNT
- zap t0, t3, t0 # e1 :
- stq_u t0, 0(a0) # e0 :
- ret # .. e1 :
-
-$multiword:
- subq t8, 1, t7 # e0 : clear the final bits in the prev
- or t7, t8, t7 # e1 : word
- zapnot t0, t7, t0 # e0 :
- subq a2, 1, a2 # .. e1 :
- stq_u t0, 0(a0) # e0 :
- addq a0, 8, a0 # .. e1 :
-
- beq a2, 1f # e1 :
- blbc a2, 0f # e1 :
-
- stq_u zero, 0(a0) # e0 : zero one word
- subq a2, 1, a2 # .. e1 :
- addq a0, 8, a0 # e0 :
- beq a2, 1f # .. e1 :
-
-0: stq_u zero, 0(a0) # e0 : zero two words
- subq a2, 2, a2 # .. e1 :
- stq_u zero, 8(a0) # e0 :
- addq a0, 16, a0 # .. e1 :
- bne a2, 0b # e1 :
- unop
-
-1: ldq_u t0, 0(a0) # e0 : clear the leading bits in the final
- subq t10, 1, t7 # .. e1 : word
- or t7, t10, t7 # e0 :
- zap t0, t7, t0 # e1 (stall)
- stq_u t0, 0(a0) # e0 :
-
-$zerocount:
- ret # .. e1 :
-
- END(strncpy)
-libc_hidden_builtin_def (strncpy)
--- a/sysdeps/alpha/alphaev67/strncat.S
+++ /dev/null
@@ -1,87 +0,0 @@
-/* Copyright (C) 2000-2020 Free Software Foundation, Inc.
- Contributed by Richard Henderson <rth@tamu.edu>, 1996.
- EV67 optimized by Rick Gorton <rick.gorton@alpha-processor.com>.
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <https://www.gnu.org/licenses/>. */
-
-/* Append no more than COUNT characters from the null-terminated string SRC
- to the null-terminated string DST. Always null-terminate the new DST. */
-
-#include <sysdep.h>
-
- .arch ev6
- .set noreorder
- .text
-
-ENTRY(strncat)
- ldgp gp, 0(pv)
-#ifdef PROF
- .set noat
- lda AT, _mcount
- jsr AT, (AT), _mcount
- .set at
-#endif
- .prologue 1
-
- mov a0, v0 # set up return value
- beq a2, $zerocount # U :
- /* Find the end of the string. */
- ldq_u t0, 0(a0) # L : load first quadword (a0 may be misaligned)
- lda t1, -1 # E :
-
- insqh t1, v0, t1 # U :
- andnot a0, 7, a0 # E :
- nop # E :
- or t1, t0, t0 # E :
-
- nop # E :
- nop # E :
- cmpbge zero, t0, t1 # E : bits set iff byte == 0
- bne t1, $found # U :
-
-$loop: ldq t0, 8(a0) # L :
- addq a0, 8, a0 # E :
- cmpbge zero, t0, t1 # E :
- beq t1, $loop # U :
-
-$found: cttz t1, t2 # U0 :
- addq a0, t2, a0 # E :
- jsr t9, __stxncpy # L0 : Now do the append.
-
- /* Worry about the null termination. */
-
- cttz t10, t2 # U0: byte offset of end-of-count.
- bic a0, 7, a0 # E : word align the last write address.
- zapnot t0, t8, t1 # U : was last byte a null?
- nop # E :
-
- bne t1, 0f # U :
- nop # E :
- nop # E :
- ret # L0 :
-
-0: addq t2, a0, a0 # E : address of end-of-count
- stb zero, 1(a0) # L :
- nop # E :
- ret # L0 :
-
-$zerocount:
- nop # E :
- nop # E :
- nop # E :
- ret # L0 :
-
- END(strncat)
--- a/sysdeps/alpha/stpncpy.S
+++ /dev/null
@@ -1,106 +0,0 @@
-/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- Contributed by Richard Henderson (rth@tamu.edu)
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <https://www.gnu.org/licenses/>. */
-
-/* Copy no more than COUNT bytes of the null-terminated string from
- SRC to DST. If SRC does not cover all of COUNT, the balance is
- zeroed. Return the address of the terminating null in DEST, if
- any, else DEST + COUNT. */
-
-#include <sysdep.h>
-
- .set noat
- .set noreorder
-
- .text
-
-ENTRY(__stpncpy)
- ldgp gp, 0(pv)
-#ifdef PROF
- lda AT, _mcount
- jsr AT, (AT), _mcount
-#endif
- .prologue 1
-
- beq a2, $zerocount
- jsr t9, __stxncpy # do the work of the copy
-
- and t8, 0xf0, t3 # binary search for byte offset of the
- and t8, 0xcc, t2 # last byte written.
- and t8, 0xaa, t1
- andnot a0, 7, v0
- cmovne t3, 4, t3
- cmovne t2, 2, t2
- cmovne t1, 1, t1
- addq v0, t3, v0
- addq t1, t2, t1
- addq v0, t1, v0
-
- bne a2, $multiword # do we have full words left?
-
- .align 3
- zapnot t0, t8, t4 # e0 : was last byte a null?
- subq t8, 1, t2 # .. e1 :
- addq v0, 1, t5 # e0 :
- subq t10, 1, t3 # .. e1 :
- or t2, t8, t2 # e0 : clear the bits between the last
- or t3, t10, t3 # .. e1 : written byte and the last byte in
- andnot t3, t2, t3 # e0 : COUNT
- cmovne t4, t5, v0 # .. e1 : if last written wasnt null, inc v0
- zap t0, t3, t0 # e0 :
- stq_u t0, 0(a0) # e1 :
- ret # .. e1 :
-
- .align 3
-$multiword:
- subq t8, 1, t7 # e0 : clear the final bits in the prev
- or t7, t8, t7 # e1 : word
- zapnot t0, t7, t0 # e0 :
- subq a2, 1, a2 # .. e1 :
- stq_u t0, 0(a0) # e0 :
- addq a0, 8, a0 # .. e1 :
-
- beq a2, 1f # e1 :
- blbc a2, 0f # e1 :
-
- stq_u zero, 0(a0) # e0 : zero one word
- subq a2, 1, a2 # .. e1 :
- addq a0, 8, a0 # e0 :
- beq a2, 1f # .. e1 :
-
-0: stq_u zero, 0(a0) # e0 : zero two words
- subq a2, 2, a2 # .. e1 :
- stq_u zero, 8(a0) # e0 :
- addq a0, 16, a0 # .. e1 :
- bne a2, 0b # e1 :
- unop
-
-1: ldq_u t0, 0(a0) # e0 : clear the leading bits in the final
- subq t10, 1, t7 # .. e1 : word
- or t7, t10, t7 # e0 :
- zap t0, t7, t0 # e1 (stall)
- stq_u t0, 0(a0) # e0 :
- ret # .. e1 :
-
-$zerocount:
- mov a0, v0
- ret
-
- END(__stpncpy)
-
-libc_hidden_def (__stpncpy)
-weak_alias (__stpncpy, stpncpy)
--- a/sysdeps/alpha/alphaev67/stpncpy.S
+++ /dev/null
@@ -1,115 +0,0 @@
-/* Copyright (C) 2000-2020 Free Software Foundation, Inc.
- Contributed by Richard Henderson (rth@redhat.com)
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <https://www.gnu.org/licenses/>. */
-
-/* Copy no more than N bytes from SRC to DEST, returning the address of
- the terminating '\0' in DEST. */
-
-#include <sysdep.h>
-
- .arch ev6
- .set noat
- .set noreorder
- .text
-
-ENTRY(__stpncpy)
- ldgp gp, 0(pv)
-#ifdef PROF
- lda AT, _mcount
- jsr AT, (AT), _mcount
-#endif
- .prologue 1
-
- mov a0, v0
- beq a2, $zerocount
-
- .align 4
- nop
- nop
- jsr t9, __stxncpy # do the work of the copy
-
- cttz t8, t4
- zapnot t0, t8, t5
- andnot a0, 7, a0
- bne a2, $multiword # do we have full words left?
-
- subq t8, 1, t2
- subq t10, 1, t3
- cmpult zero, t5, t5
- addq a0, t4, v0
-
- or t2, t8, t2
- or t3, t10, t3
- addq v0, t5, v0
- andnot t3, t2, t3
-
- zap t0, t3, t0
- nop
- stq t0, 0(a0)
- ret
-
-$multiword:
- subq t8, 1, t7 # clear the final bits in the prev word
- cmpult zero, t5, t5
- or t7, t8, t7
- zapnot t0, t7, t0
-
- subq a2, 1, a2
- stq t0, 0(a0)
- addq a0, 8, a1
- beq a2, 1f # loop over full words remaining
-
- nop
- nop
- nop
- blbc a2, 0f
-
- stq zero, 0(a1)
- subq a2, 1, a2
- addq a1, 8, a1
- beq a2, 1f
-
-0: stq zero, 0(a1)
- subq a2, 2, a2
- nop
- nop
-
- stq zero, 8(a1)
- addq a1, 16, a1
- nop
- bne a2, 0b
-
-1: ldq t0, 0(a1) # clear the leading bits in the final word
- subq t10, 1, t7
- addq a0, t4, v0
- nop
-
- or t7, t10, t7
- addq v0, t5, v0
- zap t0, t7, t0
- stq t0, 0(a1)
-
-$zerocount:
- nop
- nop
- nop
- ret
-
- END(__stpncpy)
-
-libc_hidden_def (__stpncpy)
-weak_alias (__stpncpy, stpncpy)
--- a/sysdeps/alpha/strcmp.S
+++ /dev/null
@@ -1,194 +0,0 @@
-/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
- Contributed by Richard Henderson (rth@tamu.edu)
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <https://www.gnu.org/licenses/>. */
-
-/* Bytewise compare two null-terminated strings. */
-
-#include <sysdep.h>
-
- .set noat
- .set noreorder
-
- .text
-
-ENTRY(strcmp)
-#ifdef PROF
- ldgp gp, 0(pv)
- lda AT, _mcount
- jmp AT, (AT), _mcount
- .prologue 1
-#else
- .prologue 0
-#endif
-
- ldq_u t0, 0(a0) # e0 : give cache time to catch up
- xor a0, a1, t2 # .. e1 : are s1 and s2 co-aligned?
- ldq_u t1, 0(a1) # e0 :
- and t2, 7, t2 # .. e1 :
- lda t3, -1 # e0 :
- bne t2, $unaligned # .. e1 :
-
- /* On entry to this basic block:
- t0 == the first destination word for masking back in
- t1 == the first source word.
- t3 == -1. */
-
-$aligned:
- mskqh t3, a0, t3 # e0 :
- nop # .. e1 :
- ornot t1, t3, t1 # e0 :
- ornot t0, t3, t0 # .. e1 :
- cmpbge zero, t1, t7 # e0 : bits set iff null found
- bne t7, $eos # e1 (zdb)
-
- /* Aligned compare main loop.
- On entry to this basic block:
- t0 == an s1 word.
- t1 == an s2 word not containing a null. */
-
-$a_loop:
- xor t0, t1, t2 # e0 :
- bne t2, $wordcmp # .. e1 (zdb)
- ldq_u t1, 8(a1) # e0 :
- ldq_u t0, 8(a0) # .. e1 :
- addq a1, 8, a1 # e0 :
- addq a0, 8, a0 # .. e1 :
- cmpbge zero, t1, t7 # e0 :
- beq t7, $a_loop # .. e1 (zdb)
- br $eos # e1 :
-
- /* The two strings are not co-aligned. Align s1 and cope. */
-
-$unaligned:
- and a0, 7, t4 # e0 : find s1 misalignment
- and a1, 7, t5 # .. e1 : find s2 misalignment
- subq a1, t4, a1 # e0 :
-
- /* If s2 misalignment is larger than s2 misalignment, we need
- extra startup checks to avoid SEGV. */
-
- cmplt t4, t5, t8 # .. e1 :
- beq t8, $u_head # e1 :
-
- mskqh t3, t5, t3 # e0 :
- ornot t1, t3, t3 # e0 :
- cmpbge zero, t3, t7 # e1 : is there a zero?
- beq t7, $u_head # e1 :
-
- /* We've found a zero in the first partial word of s2. Align
- our current s1 and s2 words and compare what we've got. */
-
- extql t1, t5, t1 # e0 :
- extql t0, a0, t0 # e0 :
- cmpbge zero, t1, t7 # .. e1 : find that zero again
- br $eos # e1 : and finish up
-
- .align 3
-$u_head:
- /* We know just enough now to be able to assemble the first
- full word of s2. We can still find a zero at the end of it.
-
- On entry to this basic block:
- t0 == first word of s1
- t1 == first partial word of s2. */
-
- ldq_u t2, 8(a1) # e0 : load second partial s2 word
- lda t3, -1 # .. e1 : create leading garbage mask
- extql t1, a1, t1 # e0 : create first s2 word
- mskqh t3, a0, t3 # e0 :
- extqh t2, a1, t4 # e0 :
- ornot t0, t3, t0 # .. e1 : kill s1 garbage
- or t1, t4, t1 # e0 : s2 word now complete
- cmpbge zero, t0, t7 # .. e1 : find zero in first s1 word
- ornot t1, t3, t1 # e0 : kill s2 garbage
- lda t3, -1 # .. e1 :
- mskql t3, a1, t3 # e0 : mask for s2[1] bits we have seen
- bne t7, $eos # .. e1 :
- xor t0, t1, t4 # e0 : compare aligned words
- bne t4, $wordcmp # .. e1 (zdb)
- or t2, t3, t3 # e0 :
- cmpbge zero, t3, t7 # e1 :
- bne t7, $u_final # e1 :
-
- /* Unaligned copy main loop. In order to avoid reading too much,
- the loop is structured to detect zeros in aligned words from s2.
- This has, unfortunately, effectively pulled half of a loop
- iteration out into the head and half into the tail, but it does
- prevent nastiness from accumulating in the very thing we want
- to run as fast as possible.
-
- On entry to this basic block:
- t2 == the unshifted low-bits from the next s2 word. */
-
- .align 3
-$u_loop:
- extql t2, a1, t3 # e0 :
- ldq_u t2, 16(a1) # .. e1 : load next s2 high bits
- ldq_u t0, 8(a0) # e0 : load next s1 word
- addq a1, 8, a1 # .. e1 :
- addq a0, 8, a0 # e0 :
- nop # .. e1 :
- extqh t2, a1, t1 # e0 :
- cmpbge zero, t0, t7 # .. e1 : find zero in current s1 word
- or t1, t3, t1 # e0 :
- bne t7, $eos # .. e1 :
- xor t0, t1, t4 # e0 : compare the words
- bne t4, $wordcmp # .. e1 (zdb)
- cmpbge zero, t2, t4 # e0 : find zero in next low bits
- beq t4, $u_loop # .. e1 (zdb)
-
- /* We've found a zero in the low bits of the last s2 word. Get
- the next s1 word and align them. */
-$u_final:
- ldq_u t0, 8(a0) # e1 :
- extql t2, a1, t1 # .. e0 :
- cmpbge zero, t1, t7 # e0 :
-
- /* We've found a zero somewhere in a word we just read.
- On entry to this basic block:
- t0 == s1 word
- t1 == s2 word
- t7 == cmpbge mask containing the zero. */
-
- .align 3
-$eos:
- negq t7, t6 # e0 : create bytemask of valid data
- and t6, t7, t8 # e1 :
- subq t8, 1, t6 # e0 :
- or t6, t8, t7 # e1 :
- zapnot t0, t7, t0 # e0 : kill the garbage
- zapnot t1, t7, t1 # .. e1 :
- xor t0, t1, v0 # e0 : and compare
- beq v0, $done # .. e1 :
-
- /* Here we have two differing co-aligned words in t0 & t1.
- Bytewise compare them and return (t0 > t1 ? 1 : -1). */
-$wordcmp:
- cmpbge t0, t1, t2 # e0 : comparison yields bit mask of ge
- cmpbge t1, t0, t3 # .. e1 :
- xor t2, t3, t0 # e0 : bits set iff t0/t1 bytes differ
- negq t0, t1 # e1 : clear all but least bit
- and t0, t1, t0 # e0 :
- lda v0, -1 # .. e1 :
- and t0, t2, t1 # e0 : was bit set in t0 > t1?
- cmovne t1, 1, v0 # .. e1 (zdb)
-
-$done:
- ret # e1 :
-
- END(strcmp)
-libc_hidden_builtin_def (strcmp)
--- a/sysdeps/alpha/strncmp.S
+++ /dev/null
@@ -1,277 +0,0 @@
-/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
- Contributed by Richard Henderson (rth@tamu.edu)
- This file is part of the GNU C Library.
-
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
-
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library. If not, see
- <https://www.gnu.org/licenses/>. */
-
-/* Bytewise compare two null-terminated strings of length no longer than N. */
-
-#include <sysdep.h>
-
- .set noat
- .set noreorder
-
-/* EV6 only predicts one branch per octaword. We'll use these to push
- subsequent branches back to the next bundle. This will generally add
- a fetch+decode cycle to older machines, so skip in that case. */
-#ifdef __alpha_fix__
-# define ev6_unop unop
-#else
-# define ev6_unop
-#endif
-
- .text
-
-ENTRY(strncmp)
-#ifdef PROF
- ldgp gp, 0(pv)
- lda AT, _mcount
- jsr AT, (AT), _mcount
- .prologue 1
-#else
- .prologue 0
-#endif
-
- xor a0, a1, t2 # are s1 and s2 co-aligned?
- beq a2, $zerolength
- ldq_u t0, 0(a0) # load asap to give cache time to catch up
- ldq_u t1, 0(a1)
- lda t3, -1
- and t2, 7, t2
- srl t3, 1, t6
- and a0, 7, t4 # find s1 misalignment
- and a1, 7, t5 # find s2 misalignment
- cmovlt a2, t6, a2 # bound neg count to LONG_MAX
- addq a1, a2, a3 # s2+count
- addq a2, t4, a2 # bias count by s1 misalignment
- and a2, 7, t10 # ofs of last byte in s1 last word
- srl a2, 3, a2 # remaining full words in s1 count
- bne t2, $unaligned
-
- /* On entry to this basic block:
- t0 == the first word of s1.
- t1 == the first word of s2.
- t3 == -1. */
-$aligned:
- mskqh t3, a1, t8 # mask off leading garbage
- ornot t1, t8, t1
- ornot t0, t8, t0
- cmpbge zero, t1, t7 # bits set iff null found
- beq a2, $eoc # check end of count
- bne t7, $eos
- beq t10, $ant_loop
-
- /* Aligned compare main loop.
- On entry to this basic block:
- t0 == an s1 word.
- t1 == an s2 word not containing a null. */
-
- .align 4
-$a_loop:
- xor t0, t1, t2 # e0 :
- bne t2, $wordcmp # .. e1 (zdb)
- ldq_u t1, 8(a1) # e0 :
- ldq_u t0, 8(a0) # .. e1 :
-
- subq a2, 1, a2 # e0 :
- addq a1, 8, a1 # .. e1 :
- addq a0, 8, a0 # e0 :
- beq a2, $eoc # .. e1 :
-
- cmpbge zero, t1, t7 # e0 :
- beq t7, $a_loop # .. e1 :
-
- br $eos
-
- /* Alternate aligned compare loop, for when there's no trailing
- bytes on the count. We have to avoid reading too much data. */
- .align 4
-$ant_loop:
- xor t0, t1, t2 # e0 :
- ev6_unop
- ev6_unop
- bne t2, $wordcmp # .. e1 (zdb)
-
- subq a2, 1, a2 # e0 :
- beq a2, $zerolength # .. e1 :
- ldq_u t1, 8(a1) # e0 :
- ldq_u t0, 8(a0) # .. e1 :
-
- addq a1, 8, a1 # e0 :
- addq a0, 8, a0 # .. e1 :
- cmpbge zero, t1, t7 # e0 :
- beq t7, $ant_loop # .. e1 :
-
- br $eos
-
- /* The two strings are not co-aligned. Align s1 and cope. */
- /* On entry to this basic block:
- t0 == the first word of s1.
- t1 == the first word of s2.
- t3 == -1.
- t4 == misalignment of s1.
- t5 == misalignment of s2.
- t10 == misalignment of s1 end. */
- .align 4
-$unaligned:
- /* If s1 misalignment is larger than s2 misalignment, we need
- extra startup checks to avoid SEGV. */
- subq a1, t4, a1 # adjust s2 for s1 misalignment
- cmpult t4, t5, t9
- subq a3, 1, a3 # last byte of s2
- bic a1, 7, t8
- mskqh t3, t5, t7 # mask garbage in s2
- subq a3, t8, a3
- ornot t1, t7, t7
- srl a3, 3, a3 # remaining full words in s2 count
- beq t9, $u_head
-
- /* Failing that, we need to look for both eos and eoc within the
- first word of s2. If we find either, we can continue by
- pretending that the next word of s2 is all zeros. */
- lda t2, 0 # next = zero
- cmpeq a3, 0, t8 # eoc in the first word of s2?
- cmpbge zero, t7, t7 # eos in the first word of s2?
- or t7, t8, t8
- bne t8, $u_head_nl
-
- /* We know just enough now to be able to assemble the first
- full word of s2. We can still find a zero at the end of it.
-
- On entry to this basic block:
- t0 == first word of s1
- t1 == first partial word of s2.
- t3 == -1.
- t10 == ofs of last byte in s1 last word.
- t11 == ofs of last byte in s2 last word. */
-$u_head:
- ldq_u t2, 8(a1) # load second partial s2 word
- subq a3, 1, a3
-$u_head_nl:
- extql t1, a1, t1 # create first s2 word
- mskqh t3, a0, t8
- extqh t2, a1, t4
- ornot t0, t8, t0 # kill s1 garbage
- or t1, t4, t1 # s2 word now complete
- cmpbge zero, t0, t7 # find eos in first s1 word
- ornot t1, t8, t1 # kill s2 garbage
- beq a2, $eoc
- subq a2, 1, a2
- bne t7, $eos
- mskql t3, a1, t8 # mask out s2[1] bits we have seen
- xor t0, t1, t4 # compare aligned words
- or t2, t8, t8
- bne t4, $wordcmp
- cmpbge zero, t8, t7 # eos in high bits of s2[1]?
- cmpeq a3, 0, t8 # eoc in s2[1]?
- or t7, t8, t7
- bne t7, $u_final
-
- /* Unaligned copy main loop. In order to avoid reading too much,
- the loop is structured to detect zeros in aligned words from s2.
- This has, unfortunately, effectively pulled half of a loop
- iteration out into the head and half into the tail, but it does
- prevent nastiness from accumulating in the very thing we want
- to run as fast as possible.
-
- On entry to this basic block:
- t2 == the unshifted low-bits from the next s2 word.
- t10 == ofs of last byte in s1 last word.
- t11 == ofs of last byte in s2 last word. */
- .align 4
-$u_loop:
- extql t2, a1, t3 # e0 :
- ldq_u t2, 16(a1) # .. e1 : load next s2 high bits
- ldq_u t0, 8(a0) # e0 : load next s1 word
- addq a1, 8, a1 # .. e1 :
-
- addq a0, 8, a0 # e0 :
- subq a3, 1, a3 # .. e1 :
- extqh t2, a1, t1 # e0 :
- cmpbge zero, t0, t7 # .. e1 : eos in current s1 word
-
- or t1, t3, t1 # e0 :
- beq a2, $eoc # .. e1 : eoc in current s1 word
- subq a2, 1, a2 # e0 :
- cmpbge zero, t2, t4 # .. e1 : eos in s2[1]
-
- xor t0, t1, t3 # e0 : compare the words
- ev6_unop
- ev6_unop
- bne t7, $eos # .. e1 :
-
- cmpeq a3, 0, t5 # e0 : eoc in s2[1]
- ev6_unop
- ev6_unop
- bne t3, $wordcmp # .. e1 :
-
- or t4, t5, t4 # e0 : eos or eoc in s2[1].
- beq t4, $u_loop # .. e1 (zdb)
-
- /* We've found a zero in the low bits of the last s2 word. Get
- the next s1 word and align them. */
- .align 3
-$u_final:
- ldq_u t0, 8(a0)
- extql t2, a1, t1
- cmpbge zero, t1, t7
- bne a2, $eos
-
- /* We've hit end of count. Zero everything after the count
- and compare whats left. */
- .align 3
-$eoc:
- mskql t0, t10, t0
- mskql t1, t10, t1
- cmpbge zero, t1, t7
-
- /* We've found a zero somewhere in a word we just read.
- On entry to this basic block:
- t0 == s1 word
- t1 == s2 word
- t7 == cmpbge mask containing the zero. */
- .align 3
-$eos:
- negq t7, t6 # create bytemask of valid data
- and t6, t7, t8
- subq t8, 1, t6
- or t6, t8, t7
- zapnot t0, t7, t0 # kill the garbage
- zapnot t1, t7, t1
- xor t0, t1, v0 # ... and compare
- beq v0, $done
-
- /* Here we have two differing co-aligned words in t0 & t1.
- Bytewise compare them and return (t0 > t1 ? 1 : -1). */
- .align 3
-$wordcmp:
- cmpbge t0, t1, t2 # comparison yields bit mask of ge
- cmpbge t1, t0, t3
- xor t2, t3, t0 # bits set iff t0/t1 bytes differ
- negq t0, t1 # clear all but least bit
- and t0, t1, t0
- lda v0, -1
- and t0, t2, t1 # was bit set in t0 > t1?
- cmovne t1, 1, v0
-$done:
- ret
-
- .align 3
-$zerolength:
- clr v0
- ret
-
- END(strncmp)
-libc_hidden_builtin_def (strncmp)