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Posted to commits@apr.apache.org by yl...@apache.org on 2022/01/16 13:18:35 UTC
svn commit: r1897122 - in /apr/apr/branches/1.8.x: ./ strings/ strings/apr_cstr.c
Author: ylavic
Date: Sun Jan 16 13:18:34 2022
New Revision: 1897122
URL: http://svn.apache.org/viewvc?rev=1897122&view=rev
Log:
apr_cstr: Follow up to r1897102: Yet better apr_cstr_casecmp[n]().
This ones have a shorter prologue and epilogue (-O2 still).
Dump of assembler code for function apr_cstr_casecmp:
0x0000000000049fd0 <+0>: xor %edx,%edx
0x0000000000049fd2 <+2>: lea 0x3d567(%rip),%r8 # 0x87540 <ucharmap>
0x0000000000049fd9 <+9>: nopl 0x0(%rax)
0x0000000000049fe0 <+16>: movzbl (%rsi,%rdx,1),%eax
0x0000000000049fe4 <+20>: movzbl (%r8,%rax,1),%ecx
0x0000000000049fe9 <+25>: movzbl (%rdi,%rdx,1),%eax
0x0000000000049fed <+29>: add $0x1,%rdx
0x0000000000049ff1 <+33>: movzbl (%r8,%rax,1),%eax
0x0000000000049ff6 <+38>: sub %ecx,%eax
0x0000000000049ff8 <+40>: jne 0x49ffe <apr_cstr_casecmp+46>
0x0000000000049ffa <+42>: test %ecx,%ecx
0x0000000000049ffc <+44>: jne 0x49fe0 <apr_cstr_casecmp+16>
0x0000000000049ffe <+46>: ret
End of assembler dump.
Merge r1897121 from trunk.
Submitted by: ylavic
Modified:
apr/apr/branches/1.8.x/ (props changed)
apr/apr/branches/1.8.x/strings/ (props changed)
apr/apr/branches/1.8.x/strings/apr_cstr.c
Propchange: apr/apr/branches/1.8.x/
------------------------------------------------------------------------------
Merged /apr/apr/trunk:r1897121
Propchange: apr/apr/branches/1.8.x/strings/
------------------------------------------------------------------------------
Merged /apr/apr/trunk/strings:r1897121
Modified: apr/apr/branches/1.8.x/strings/apr_cstr.c
URL: http://svn.apache.org/viewvc/apr/apr/branches/1.8.x/strings/apr_cstr.c?rev=1897122&r1=1897121&r2=1897122&view=diff
==============================================================================
--- apr/apr/branches/1.8.x/strings/apr_cstr.c (original)
+++ apr/apr/branches/1.8.x/strings/apr_cstr.c Sun Jan 16 13:18:34 2022
@@ -282,25 +282,27 @@ static const unsigned char ucharmap[256]
APR_DECLARE(int) apr_cstr_casecmp(const char *s1, const char *s2)
{
- apr_size_t i = 0;
- for (;; ++i) {
- const int c1 = ucharmap[(unsigned char)s1[i]];
- const int c2 = ucharmap[(unsigned char)s2[i]];
- /* Not necessary to test for !c2, this is caught by c1 != c2 */
- if (c1 != c2 || !c1)
- return c1 - c2;
+ const unsigned char *u1 = (const unsigned char *)s1;
+ const unsigned char *u2 = (const unsigned char *)s2;
+ for (;;) {
+ const int c2 = ucharmap[*u2++];
+ const int cmp = (int)ucharmap[*u1++] - c2;
+ /* Not necessary to test for !c1, this is caught by cmp */
+ if (cmp || !c2)
+ return cmp;
}
}
APR_DECLARE(int) apr_cstr_casecmpn(const char *s1, const char *s2, apr_size_t n)
{
- apr_size_t i = 0;
- for (; i < n; ++i) {
- const int c1 = ucharmap[(unsigned char)s1[i]];
- const int c2 = ucharmap[(unsigned char)s2[i]];
- /* Not necessary to test for !c2, this is caught by c1 != c2 */
- if (c1 != c2 || !c1)
- return c1 - c2;
+ const unsigned char *u1 = (const unsigned char *)s1;
+ const unsigned char *u2 = (const unsigned char *)s2;
+ while (n--) {
+ const int c2 = ucharmap[*u2++];
+ const int cmp = (int)ucharmap[*u1++] - c2;
+ /* Not necessary to test for !c1, this is caught by cmp */
+ if (cmp || !c2)
+ return cmp;
}
return 0;
}