Revert "Merge branch 'dt/refs-check-refname-component-sse'"

This reverts commit 6f92e5ff3cdc813de8ef5327fd4bad492fb7d6c9, reversing
changes made to a02ad882a17b9d45f63ea448391ac5e9f7948222.

1 files changed, 18 insertions, 216 deletions

diff --git a/refs.c b/refs.c
index 3b030e6..27927f2 100644
--- a/refs.c
+++ b/refs.c
@@ -7,27 +7,21 @@
 
 /*
  * How to handle various characters in refnames:
- * This table is used by both the SIMD and non-SIMD code.  It has
- * some cases that are only useful for the SIMD; these are handled
- * equivalently to the listed disposition in the non-SIMD code.
  * 0: An acceptable character for refs
- * 1: @, look for a following { to reject @{ in refs (SIMD or = 0)
- * 2: \0: End-of-component and string
- * 3: /: End-of-component (SIMD or = 2)
- * 4: ., look for a preceding . to reject .. in refs
- * 5: {, look for a preceding @ to reject @{ in refs
- * 6: *, usually a bad character except, once as a wildcard (SIMD or = 7)
- * 7: A bad character except * (see check_refname_component below)
+ * 1: End-of-component
+ * 2: ., look for a preceding . to reject .. in refs
+ * 3: {, look for a preceding @ to reject @{ in refs
+ * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
  */
 static unsigned char refname_disposition[256] = {
-	2, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-	7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-	7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 4, 3,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 7,
-	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 7, 0, 7, 0,
+	1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+	4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+	4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 7, 7
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
 };
 
 /*
@@ -39,9 +33,8 @@ static unsigned char refname_disposition[256] = {
  * - any path component of it begins with ".", or
  * - it has double dots "..", or
  * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
- * - it has pattern-matching notation "*", "?", "[", anywhere, or
- * - it ends with a "/", or
- * - it ends with ".lock", or
+ * - it ends with a "/".
+ * - it ends with ".lock"
  * - it contains a "\" (backslash)
  */
 static int check_refname_component(const char *refname, int flags)
@@ -53,19 +46,17 @@ static int check_refname_component(const char *refname, int flags)
 		int ch = *cp & 255;
 		unsigned char disp = refname_disposition[ch];
 		switch (disp) {
-		case 2: /* fall-through */
-		case 3:
+		case 1:
 			goto out;
-		case 4:
+		case 2:
 			if (last == '.')
 				return -1; /* Refname contains "..". */
 			break;
-		case 5:
+		case 3:
 			if (last == '@')
 				return -1; /* Refname contains "@{". */
 			break;
-		case 6: /* fall-through */
-		case 7:
+		case 4:
 			return -1;
 		}
 		last = ch;
@@ -88,7 +79,7 @@ out:
 	return cp - refname;
 }
 
-static int check_refname_format_bytewise(const char *refname, int flags)
+int check_refname_format(const char *refname, int flags)
 {
 	int component_len, component_count = 0;
 
@@ -124,195 +115,6 @@ static int check_refname_format_bytewise(const char *refname, int flags)
 	return 0;
 }
 
-#if defined(__GNUC__) && defined(__x86_64__)
-#define SSE_VECTOR_BYTES 16
-
-/* Vectorized version of check_refname_format. */
-int check_refname_format(const char *refname, int flags)
-{
-	const char *cp = refname;
-
-	const __m128i dot = _mm_set1_epi8('.');
-	const __m128i at = _mm_set1_epi8('@');
-	const __m128i curly = _mm_set1_epi8('{');
-	const __m128i slash = _mm_set1_epi8('/');
-	const __m128i zero = _mm_set1_epi8('\000');
-	const __m128i el = _mm_set1_epi8('l');
-
-	/* below '*', all characters are forbidden or rare */
-	const __m128i star_ub = _mm_set1_epi8('*' + 1);
-
-	const __m128i colon = _mm_set1_epi8(':');
-	const __m128i question = _mm_set1_epi8('?');
-
-	/* '['..'^' contains 4 characters: 3 forbidden and 1 rare */
-	const __m128i bracket_lb = _mm_set1_epi8('[' - 1);
-	const __m128i caret_ub = _mm_set1_epi8('^' + 1);
-
-	/* '~' and above are forbidden */
-	const __m128i tilde_lb = _mm_set1_epi8('~' - 1);
-
-	int component_count = 0;
-
-	if (refname[0] == 0 || refname[0] == '/') {
-		/* entirely empty ref or initial ref component */
-		return -1;
-	}
-
-	/*
-	 * Initial ref component of '.'; below we look for /. so we'll
-	 * miss this.
-	 */
-	if (refname[0] == '.') {
-		if (refname[1] == '/' || refname[1] == '\0')
-			return -1;
-		if (!(flags & REFNAME_DOT_COMPONENT))
-			return -1;
-	}
-	while(1) {
-		__m128i tmp, tmp1, result;
-		uint64_t mask;
-
-		if ((uintptr_t) cp % PAGE_SIZE > PAGE_SIZE - SSE_VECTOR_BYTES  - 1)
-			/*
-			 * End-of-page; fall back to slow method for
-			 * this entire ref.
-			 */
-			return check_refname_format_bytewise(refname, flags);
-
-		tmp = _mm_loadu_si128((__m128i *)cp);
-		tmp1 = _mm_loadu_si128((__m128i *)(cp + 1));
-
-		/*
-		 * This range (note the lt) contains some
-		 * permissible-but-rare characters (including all
-		 * characters >= 128), which we handle later.  It also
-		 * includes \000.
-		 */
-		result = _mm_cmplt_epi8(tmp, star_ub);
-
-		result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, question));
-		result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, colon));
-
-		/* This range contains the permissible ] as bycatch */
-		result = _mm_or_si128(result, _mm_and_si128(
-					      _mm_cmpgt_epi8(tmp, bracket_lb),
-					      _mm_cmplt_epi8(tmp, caret_ub)));
-
-		result = _mm_or_si128(result, _mm_cmpgt_epi8(tmp, tilde_lb));
-
-		/* .. */
-		result = _mm_or_si128(result, _mm_and_si128(
-					      _mm_cmpeq_epi8(tmp, dot),
-					      _mm_cmpeq_epi8(tmp1, dot)));
-		/* @{ */
-		result = _mm_or_si128(result, _mm_and_si128(
-					      _mm_cmpeq_epi8(tmp, at),
-					      _mm_cmpeq_epi8(tmp1, curly)));
-		/* // */
-		result = _mm_or_si128(result, _mm_and_si128(
-					      _mm_cmpeq_epi8(tmp, slash),
-					      _mm_cmpeq_epi8(tmp1, slash)));
-		/* trailing / */
-		result = _mm_or_si128(result, _mm_and_si128(
-					      _mm_cmpeq_epi8(tmp, slash),
-					      _mm_cmpeq_epi8(tmp1, zero)));
-		/* .l, beginning of .lock */
-		result = _mm_or_si128(result, _mm_and_si128(
-					      _mm_cmpeq_epi8(tmp, dot),
-					      _mm_cmpeq_epi8(tmp1, el)));
-		/*
-		 * Even though /. is not necessarily an error, we flag
-		 * it anyway. If we find it, we'll check if it's valid
-		 * and if so we'll advance just past it.
-		 */
-		result = _mm_or_si128(result, _mm_and_si128(
-					      _mm_cmpeq_epi8(tmp, slash),
-					      _mm_cmpeq_epi8(tmp1, dot)));
-
-		mask = _mm_movemask_epi8(result);
-		if (mask) {
-			/*
-			 * We've found either end-of-string, or some
-			 * probably-bad character or substring.
-			 */
-			int i = __builtin_ctz(mask);
-			switch (refname_disposition[cp[i] & 255]) {
-			case 0: /* fall-through */
-			case 5:
-				/*
-				 * bycatch: a good character that's in
-				 * one of the ranges of mostly-forbidden
-				 * characters
-				 */
-				cp += i + 1;
-				break;
-			case 1:
-				if (cp[i + 1] == '{')
-					return -1;
-				cp += i + 1;
-				break;
-			case 2:
-				if (!(flags & REFNAME_ALLOW_ONELEVEL)
-				    && !component_count && !strchr(refname, '/'))
-					/* Refname has only one component. */
-					return -1;
-				return 0;
-			case 3:
-				component_count ++;
-				/*
-				 * Even if leading dots are allowed, don't
-				 * allow "." as a component (".." is
-				 * prevented by case 4 below).
-				 */
-				if (cp[i + 1] == '.') {
-					if (cp[i + 2] == '\0')
-						return -1;
-					if (flags & REFNAME_DOT_COMPONENT) {
-						/* skip to just after the /. */
-						cp += i + 2;
-						break;
-					}
-					return -1;
-				} else if (cp[i + 1] == '/' || cp[i + 1] == '\0')
-					return -1;
-				break;
-			case 4:
-				if (cp[i + 1] == '.' || cp[i + 1] == '\0')
-					return -1;
-				/* .lock as end-of-component or end-of-string */
-				if ((!strncmp(cp + i, ".lock", 5))
-				    && (cp[i + 5] == '/' || cp[i + 5] == 0))
-					return -1;
-				cp += 1;
-				break;
-			case 6:
-				if (((cp == refname + i) || cp[i - 1] == '/')
-				    && (cp[i + 1] == '/' || cp[i + 1] == 0))
-					if (flags & REFNAME_REFSPEC_PATTERN) {
-						flags &= ~REFNAME_REFSPEC_PATTERN;
-						/* restart after the * */
-						cp += i + 1;
-						continue;
-					}
-				/* fall-through */
-			case 7:
-				return -1;
-			}
-		} else
-			cp += SSE_VECTOR_BYTES;
-	}
-}
-
-#else
-
-int check_refname_format (const char *refname, int flags)
-{
-	return check_refname_format_bytewise(refname, flags);
-}
-
-#endif
-
 struct ref_entry;
 
 /*