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* [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops @ 2020-05-15 12:32 hjl.tools at gmail dot com 2020-05-19 12:11 ` [Bug target/95151] [9/10/11 Regression] " hjl.tools at gmail dot com ` (9 more replies) 0 siblings, 10 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-05-15 12:32 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 Bug ID: 95151 Summary: Add cmpmemM pattern for -minline-all-stringops Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: hjl.tools at gmail dot com CC: crazylht at gmail dot com Target Milestone: --- Target: i386,x86-64 'cmpmemM' Block compare instruction, with five operands like the operands of 'cmpstrM'. The two memory blocks specified are compared byte by byte in lexicographic order starting at the beginning of each block. Unlike 'cmpstrM' the instruction can prefetch any bytes in the two memory blocks. Also unlike 'cmpstrM' the comparison will not stop if both bytes are zero. The effect of the instruction is to store a value in operand 0 whose sign indicates the result of the comparison. We should add (define_expand "cmpmemsi" [(set (match_operand:SI 0 "register_operand" "") (compare:SI (match_operand:BLK 1 "memory_operand" "") (match_operand:BLK 2 "memory_operand" "") ) ) (use (match_operand 3 "general_operand")) (use (match_operand 4 "immediate_operand"))] "" { if (ix86_expand_cmpmem (operands[0], operands[1], operands[2], operands[3])) DONE; else FAIL; }) which can be expanded to sysdeps/i386/memcmp.S in glibc: movl BLK1(%esp), %esi cfi_rel_offset (esi, 0) movl BLK2(%esp), %edi movl LEN(%esp), %ecx cld /* Set direction of comparison. */ xorl %eax, %eax /* Default result. */ repe /* Compare at most %ecx bytes. */ cmpsb jz L(1) /* If even last byte was equal we return 0. */ /* The memory blocks are not equal. So result of the last subtraction is present in the carry flag. It is set when the byte in block #2 is bigger. In this case we have to return -1 (=0xffffffff), else 1. */ sbbl %eax, %eax /* This is tricky. %eax == 0 and carry is set or not depending on last subtraction. */ /* At this point %eax == 0, if the byte of block #1 was bigger, and 0xffffffff if the last byte of block #2 was bigger. The latter case is already correct but the former needs a little adjustment. Note that the following operation does not change 0xffffffff. */ orb $1, %al /* Change 0 to 1. */ L(1): ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com @ 2020-05-19 12:11 ` hjl.tools at gmail dot com 2020-05-30 12:14 ` hjl.tools at gmail dot com ` (8 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-05-19 12:11 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|Add cmpmemM pattern for |[9/10/11 Regression] Add |-minline-all-stringops |cmpmemM pattern for | |-minline-all-stringops Target Milestone|--- |11.0 Status|UNCONFIRMED |NEW Ever confirmed|0 |1 Last reconfirmed| |2020-05-19 --- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> --- We used to expand memcmp to "repz cmpsb" via cmpstrnsi. It was changed by commit 9b0f6f5e511ca512e4faeabc81d2fd3abad9b02f Author: Nick Clifton <nickc@redhat.com> Date: Fri Aug 12 16:26:11 2011 +0000 builtins.c (expand_builtin_memcmp): Do not use cmpstrnsi pattern. * builtins.c (expand_builtin_memcmp): Do not use cmpstrnsi pattern. * doc/md.texi (cmpstrn): Note that the comparison stops if both fetched bytes are zero. (cmpstr): Likewise. (cmpmem): Note that the comparison does not stop if both of the fetched bytes are zero. ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com 2020-05-19 12:11 ` [Bug target/95151] [9/10/11 Regression] " hjl.tools at gmail dot com @ 2020-05-30 12:14 ` hjl.tools at gmail dot com 2020-05-31 1:40 ` hjl.tools at gmail dot com ` (7 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-05-30 12:14 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 --- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> --- Initial attempt failed on [hjl@gnu-cfl-2 pr95151]$ cat saved.c #include <stdint.h> #include <string.h> #include <sys/mman.h> #include <unistd.h> unsigned char *buf1, *buf2; int ret; size_t page_size; static void do_one_test (char *dst, char *src, const char *orig_src, size_t len) { memcpy (src, orig_src, len); memmove (dst, src, len); if (memcmp (dst, orig_src, len) != 0) { ret = 1; return; } } void __attribute__ ((noclone, noinline)) do_test (char *s1, char *s2, int n, size_t len) { int i; for (i = 0; i < n; i++) do_one_test (s2, s2, s1, len); } int main (void) { page_size = 2 * getpagesize (); buf1 = mmap (0, (1 + 1) * page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); if (buf1 == MAP_FAILED) return -1; if (mprotect (buf1 + 1 * page_size, page_size, PROT_NONE)) return -1; buf2 = mmap (0, 2 * page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); if (buf2 == MAP_FAILED) return -1; if (mprotect (buf2 + page_size, page_size, PROT_NONE)) return -1; memset (buf1, 0xa5, 1 * page_size); memset (buf2, 0x5a, page_size); char *s1 = (char *) buf1; char *s2 = (char *) buf2; size_t len; size_t i, j; len = 1 << 2; for (i = 0, j = 1; i < len; i++, j += 23) s1[i] = j; do_test (s1, s2, 10, 1 << 2); len = 1 << 4; for (i = 0, j = 1; i < len; i++, j += 23) s1[i] = j; do_test (s1, s2, 10, 1 << 4); return ret; } [hjl@gnu-cfl-2 pr95151]$ make saved /export/build/gnu/tools-build/gcc-gitlab-release-debug/build-x86_64-linux/gcc/xgcc -B/export/build/gnu/tools-build/gcc-gitlab-release-debug/build-x86_64-linux/gcc/ -O2 -minline-all-stringops saved.c -o saved [hjl@gnu-cfl-2 pr95151]$ ./saved Segmentation fault (core dumped) [hjl@gnu-cfl-2 pr95151]$ ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com 2020-05-19 12:11 ` [Bug target/95151] [9/10/11 Regression] " hjl.tools at gmail dot com 2020-05-30 12:14 ` hjl.tools at gmail dot com @ 2020-05-31 1:40 ` hjl.tools at gmail dot com 2020-05-31 23:13 ` hjl.tools at gmail dot com ` (6 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-05-31 1:40 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 Bug 95151 depends on bug 95439, which changed state. Bug 95439 Summary: Incorrect zero count check in cmpstrnsi https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95439 What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com ` (2 preceding siblings ...) 2020-05-31 1:40 ` hjl.tools at gmail dot com @ 2020-05-31 23:13 ` hjl.tools at gmail dot com 2020-05-31 23:14 ` hjl.tools at gmail dot com ` (5 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-05-31 23:13 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 Bug 95151 depends on bug 95444, which changed state. Bug 95444 Summary: Incorrect constraints on length operand in cmpstrnqi patterns https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95444 What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com ` (3 preceding siblings ...) 2020-05-31 23:13 ` hjl.tools at gmail dot com @ 2020-05-31 23:14 ` hjl.tools at gmail dot com 2020-07-13 17:35 ` hjl.tools at gmail dot com ` (4 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-05-31 23:14 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |patch URL| |https://gcc.gnu.org/piperma | |il/gcc-patches/2020-May/546 | |919.html Depends on|95444 | --- Comment #3 from H.J. Lu <hjl.tools at gmail dot com> --- A patch is posted at https://gcc.gnu.org/pipermail/gcc-patches/2020-May/546919.html Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95444 [Bug 95444] Incorrect constraints on length operand in cmpstrnqi patterns ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com ` (4 preceding siblings ...) 2020-05-31 23:14 ` hjl.tools at gmail dot com @ 2020-07-13 17:35 ` hjl.tools at gmail dot com 2020-07-14 19:10 ` ro at gcc dot gnu.org ` (3 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-07-13 17:35 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 Bug 95151 depends on bug 95443, which changed state. Bug 95443 Summary: cmpstrnqi patterns update string length https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95443 What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |FIXED ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com ` (5 preceding siblings ...) 2020-07-13 17:35 ` hjl.tools at gmail dot com @ 2020-07-14 19:10 ` ro at gcc dot gnu.org 2020-07-14 21:08 ` hjl.tools at gmail dot com ` (2 subsequent siblings) 9 siblings, 0 replies; 11+ messages in thread From: ro at gcc dot gnu.org @ 2020-07-14 19:10 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 Bug 95151 depends on bug 95443, which changed state. Bug 95443 Summary: cmpstrnqi patterns update string length https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95443 What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED Resolution|FIXED |--- ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com ` (6 preceding siblings ...) 2020-07-14 19:10 ` ro at gcc dot gnu.org @ 2020-07-14 21:08 ` hjl.tools at gmail dot com 2020-10-16 11:43 ` rguenth at gcc dot gnu.org 2020-10-26 11:19 ` hjl.tools at gmail dot com 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-07-14 21:08 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 Bug 95151 depends on bug 95443, which changed state. Bug 95443 Summary: cmpstrnqi patterns update string length https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95443 What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED Resolution|--- |FIXED ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com ` (7 preceding siblings ...) 2020-07-14 21:08 ` hjl.tools at gmail dot com @ 2020-10-16 11:43 ` rguenth at gcc dot gnu.org 2020-10-26 11:19 ` hjl.tools at gmail dot com 9 siblings, 0 replies; 11+ messages in thread From: rguenth at gcc dot gnu.org @ 2020-10-16 11:43 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P3 |P2 ^ permalink raw reply [flat|nested] 11+ messages in thread
* [Bug target/95151] [9/10/11 Regression] Add cmpmemM pattern for -minline-all-stringops 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com ` (8 preceding siblings ...) 2020-10-16 11:43 ` rguenth at gcc dot gnu.org @ 2020-10-26 11:19 ` hjl.tools at gmail dot com 9 siblings, 0 replies; 11+ messages in thread From: hjl.tools at gmail dot com @ 2020-10-26 11:19 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95151 H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #4 from H.J. Lu <hjl.tools at gmail dot com> --- Fixed for GCC 11 by commit 3edc21af5272194794fbf24b2c5f0981c632e866 Author: H.J. Lu <hjl.tools@gmail.com> Date: Thu May 14 13:06:23 2020 -0700 x86: Add cmpmemsi for -minline-all-stringops ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2020-10-26 11:19 UTC | newest] Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-05-15 12:32 [Bug target/95151] New: Add cmpmemM pattern for -minline-all-stringops hjl.tools at gmail dot com 2020-05-19 12:11 ` [Bug target/95151] [9/10/11 Regression] " hjl.tools at gmail dot com 2020-05-30 12:14 ` hjl.tools at gmail dot com 2020-05-31 1:40 ` hjl.tools at gmail dot com 2020-05-31 23:13 ` hjl.tools at gmail dot com 2020-05-31 23:14 ` hjl.tools at gmail dot com 2020-07-13 17:35 ` hjl.tools at gmail dot com 2020-07-14 19:10 ` ro at gcc dot gnu.org 2020-07-14 21:08 ` hjl.tools at gmail dot com 2020-10-16 11:43 ` rguenth at gcc dot gnu.org 2020-10-26 11:19 ` hjl.tools at gmail dot com
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