Message ID | CAFULd4a=HVQrmm9wEsoSgPEeVB6x9U+yJk1OjUOsTSeiiquJQw@mail.gmail.com |
---|---|
State | New |
Headers | show |
On 2012-06-18 13:19, Uros Bizjak wrote: > /* ??? The builtin doesn't understand that the PCMPESTRI read from > memory need not be aligned. */ > - __asm ("%vpcmpestri $0, (%1), %2" > - : "=c"(index) : "r"(s), "x"(search), "a"(4), "d"(16)); > + sv = __builtin_ia32_loaddqu ((const char *) s); > + index = __builtin_ia32_pcmpestri128 (search, 4, sv, 16, 0); > + Surely the comment can be removed too then? r~
On Tue, Jun 19, 2012 at 12:07 AM, Richard Henderson <rth@redhat.com> wrote: > On 2012-06-18 13:19, Uros Bizjak wrote: >> /* ??? The builtin doesn't understand that the PCMPESTRI read from >> memory need not be aligned. */ >> - __asm ("%vpcmpestri $0, (%1), %2" >> - : "=c"(index) : "r"(s), "x"(search), "a"(4), "d"(16)); >> + sv = __builtin_ia32_loaddqu ((const char *) s); >> + index = __builtin_ia32_pcmpestri128 (search, 4, sv, 16, 0); >> + > > > Surely the comment can be removed too then? I'm not sure there. The builtin, as defined, expects V16QI operand with xm constraint. Using: int test (const char *s1) { const v16qi *p = (const v16qi *)(unsigned long) s1; return __builtin_ia32_pcmpistri128 (*p, ...); } will generate movdqa before pcmpistri. With x86 pcmp[ie]str patch, we trick gcc to pass unaligned memory to the pcmp[ie]str RTX, but we still need __builtin_ia32_loaddqu in front of __builtin_ia32_pcmpestri128. Uros.
On Tue, Jun 19, 2012 at 8:38 AM, Uros Bizjak <ubizjak@gmail.com> wrote: > On Tue, Jun 19, 2012 at 12:07 AM, Richard Henderson <rth@redhat.com> wrote: >> On 2012-06-18 13:19, Uros Bizjak wrote: >>> /* ??? The builtin doesn't understand that the PCMPESTRI read from >>> memory need not be aligned. */ >>> - __asm ("%vpcmpestri $0, (%1), %2" >>> - : "=c"(index) : "r"(s), "x"(search), "a"(4), "d"(16)); >>> + sv = __builtin_ia32_loaddqu ((const char *) s); >>> + index = __builtin_ia32_pcmpestri128 (search, 4, sv, 16, 0); >>> + >> >> >> Surely the comment can be removed too then? > > I'm not sure there. The builtin, as defined, expects V16QI operand > with xm constraint. Using: > > int test (const char *s1) > { > const v16qi *p = (const v16qi *)(unsigned long) s1; > return __builtin_ia32_pcmpistri128 (*p, ...); > } > > will generate movdqa before pcmpistri. Pedantic correction: __builtin_ia32_pcmpistri128 (v16qi_arg, *p, N); movdqa in front of this builtin will be generated with -O0. Uros.
On 2012-06-18 23:38, Uros Bizjak wrote: > On Tue, Jun 19, 2012 at 12:07 AM, Richard Henderson <rth@redhat.com> wrote: >> On 2012-06-18 13:19, Uros Bizjak wrote: >>> /* ??? The builtin doesn't understand that the PCMPESTRI read from >>> memory need not be aligned. */ >>> - __asm ("%vpcmpestri $0, (%1), %2" >>> - : "=c"(index) : "r"(s), "x"(search), "a"(4), "d"(16)); >>> + sv = __builtin_ia32_loaddqu ((const char *) s); >>> + index = __builtin_ia32_pcmpestri128 (search, 4, sv, 16, 0); >>> + >> >> >> Surely the comment can be removed too then? > > I'm not sure there. The builtin, as defined, expects V16QI operand > with xm constraint. Fair enough. I'm ok with the patch as-is. r~
Index: lex.c =================================================================== --- lex.c (revision 188750) +++ lex.c (working copy) @@ -420,6 +420,7 @@ search_line_sse42 (const uchar *s, const uchar *en { typedef char v16qi __attribute__ ((__vector_size__ (16))); static const v16qi search = { '\n', '\r', '?', '\\' }; + v16qi sv; uintptr_t si = (uintptr_t)s; uintptr_t index; @@ -439,8 +440,9 @@ search_line_sse42 (const uchar *s, const uchar *en /* ??? The builtin doesn't understand that the PCMPESTRI read from memory need not be aligned. */ - __asm ("%vpcmpestri $0, (%1), %2" - : "=c"(index) : "r"(s), "x"(search), "a"(4), "d"(16)); + sv = __builtin_ia32_loaddqu ((const char *) s); + index = __builtin_ia32_pcmpestri128 (search, 4, sv, 16, 0); + if (__builtin_expect (index < 16, 0)) goto found;