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Fix noodle spurious match with \0 chars for SVE2

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When sve2's noodle process a non full vector (before the main loop or
at the end of it), a fake \0 was being parsed, trigerring a match for
pattern that ended with \0. This patch fix this.

Signed-off-by: Yoan Picchi <yoan.picchi@arm.com>
This commit is contained in:
Yoan Picchi 2024-08-09 13:15:56 +00:00
parent 883c19243c
commit 4468062735
1 changed files with 34 additions and 12 deletions
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46
src/hwlm/noodle_engine_sve.hpp
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@ -148,15 +148,14 @@ hwlm_error_t doubleCheckMatched(const struct noodTable *n, const u8 *buf,
} }
static really_inline static really_inline
svbool_t doubleMatched(svuint16_t chars, const u8 *d, svbool_t doubleMatchedLoop(svuint16_t chars, const u8 *d,
svbool_t pg, svbool_t pg_rot,
svbool_t * const matched, svbool_t * const matched_rot) { svbool_t * const matched, svbool_t * const matched_rot) {
svuint16_t vec = svreinterpret_u16(svld1_u8(pg, d)); svuint16_t vec = svreinterpret_u16(svld1_u8(svptrue_b8(), d));
// d - 1 won't underflow as the first position in buf has been dealt // d - 1 won't underflow as the first position in buf has been dealt
// with meaning that d > buf // with meaning that d > buf
svuint16_t vec_rot = svreinterpret_u16(svld1_u8(pg_rot, d - 1)); svuint16_t vec_rot = svreinterpret_u16(svld1_u8(svptrue_b8(), d - 1));
*matched = svmatch(pg, vec, chars); *matched = svmatch(svptrue_b8(), vec, chars);
*matched_rot = svmatch(pg_rot, vec_rot, chars); *matched_rot = svmatch(svptrue_b8(), vec_rot, chars);
return svorr_z(svptrue_b8(), *matched, *matched_rot); return svorr_z(svptrue_b8(), *matched, *matched_rot);
} }
@ -167,10 +166,34 @@ hwlm_error_t scanDoubleOnce(const struct noodTable *n, const u8 *buf,
DEBUG_PRINTF("start %p end %p\n", d, e); DEBUG_PRINTF("start %p end %p\n", d, e);
assert(d < e); assert(d < e);
assert(d > buf); assert(d > buf);
svbool_t pg = svwhilelt_b8_s64(0, e - d); const ptrdiff_t size = e - d;
svbool_t pg_rot = svwhilelt_b8_s64(0, e - d + 1); svbool_t pg = svwhilelt_b8_s64(0, size);
svbool_t matched, matched_rot; svbool_t pg_rot = svwhilelt_b8_s64(0, size + 1);
svbool_t any = doubleMatched(svreinterpret_u16(chars), d, pg, pg_rot, &matched, &matched_rot);
svuint16_t vec = svreinterpret_u16(svld1_u8(pg, d));
// d - 1 won't underflow as the first position in buf has been dealt
// with meaning that d > buf
svuint16_t vec_rot = svreinterpret_u16(svld1_u8(pg_rot, d - 1));
// we reuse u8 predicates for u16 lanes. This means that we will check against one
// extra \0 character at the end of the vector.
if(unlikely(n->key1 == '\0')) {
if (size % 2) {
// if odd, vec has an odd number of lanes and has the spurious \0
svbool_t lane_to_disable = svrev_b8(svpfirst(svrev_b8(pg), svpfalse()));
pg = sveor_z(svptrue_b8(), pg, lane_to_disable);
} else {
// if even, vec_rot has an odd number of lanes and has the spurious \0
// we need to disable the last active lane as well, but we know pg is
// the same as pg_rot without the last lane
pg_rot = pg;
}
}
svbool_t matched = svmatch(pg, vec, svreinterpret_u16(chars));
svbool_t matched_rot = svmatch(pg_rot, vec_rot, svreinterpret_u16(chars));
svbool_t any = svorr_z(svptrue_b8(), matched, matched_rot);
return doubleCheckMatched(n, buf, len, cbi, d, matched, matched_rot, any); return doubleCheckMatched(n, buf, len, cbi, d, matched, matched_rot, any);
} }
@ -187,8 +210,7 @@ hwlm_error_t scanDoubleLoop(const struct noodTable *n, const u8 *buf,
for (size_t i = 0; i < loops; i++, d += svcntb()) { for (size_t i = 0; i < loops; i++, d += svcntb()) {
DEBUG_PRINTF("d %p \n", d); DEBUG_PRINTF("d %p \n", d);
svbool_t matched, matched_rot; svbool_t matched, matched_rot;
svbool_t any = doubleMatched(svreinterpret_u16(chars), d, svptrue_b8(), svptrue_b8(), svbool_t any = doubleMatchedLoop(svreinterpret_u16(chars), d, &matched, &matched_rot);
&matched, &matched_rot);
hwlm_error_t rv = doubleCheckMatched(n, buf, len, cbi, d, hwlm_error_t rv = doubleCheckMatched(n, buf, len, cbi, d,
matched, matched_rot, any); matched, matched_rot, any);
RETURN_IF_TERMINATED(rv); RETURN_IF_TERMINATED(rv);