Backport fix for PR 80769
2017-08-01 Richard Sandiford <richard.sandiford@linaro.org> gcc/ PR tree-optimization/80769 * tree-ssa-strlen.c (strinfo): Document that "stmt" is also used for malloc and calloc. Document the new invariant that all related strinfos have delayed lengths or none do. (get_next_strinfo): New function. (verify_related_strinfos): Move earlier in file. (set_endptr_and_length): New function, split out from... (get_string_length): ...here. Also set the lengths of related strinfos. gcc/testsuite/ PR tree-optimization/80769 * gcc.dg/strlenopt-31.c: New test. * gcc.dg/strlenopt-31g.c: Likewise. From-SVN: r250772
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2017-08-01 Richard Sandiford <richard.sandiford@linaro.org>
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PR tree-optimization/80769
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* tree-ssa-strlen.c (strinfo): Document that "stmt" is also used
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for malloc and calloc. Document the new invariant that all related
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strinfos have delayed lengths or none do.
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(get_next_strinfo): New function.
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(verify_related_strinfos): Move earlier in file.
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(set_endptr_and_length): New function, split out from...
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(get_string_length): ...here. Also set the lengths of related
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strinfos.
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2017-08-01 Jakub Jelinek <jakub@redhat.com>
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PR tree-optimization/81588
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@ -1,3 +1,9 @@
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2017-08-01 Richard Sandiford <richard.sandiford@linaro.org>
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PR tree-optimization/80769
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* gcc.dg/strlenopt-31.c: New test.
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* gcc.dg/strlenopt-31g.c: Likewise.
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2017-08-01 Jakub Jelinek <jakub@redhat.com>
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PR tree-optimization/81588
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/* { dg-do run } */
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/* { dg-options "-O2" } */
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#include "strlenopt.h"
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__attribute__((noinline, noclone)) int
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bar (char *p1, const char *q)
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{
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strcpy (p1, "abcde");
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char *p2 = strchr (p1, '\0');
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strcpy (p2, q);
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char *p3 = strchr (p2, '\0');
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memcpy (p3, "x", 2);
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return strlen (p1);
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}
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int
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main (void)
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{
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char buffer[10];
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int res = bar (buffer, "foo");
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if (strcmp (buffer, "abcdefoox") != 0 || res != 9)
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abort ();
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return 0;
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}
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@ -0,0 +1,9 @@
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/* { dg-do run { target *-*-linux* *-*-gnu* } } */
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/* { dg-options "-O2 -fdump-tree-strlen" } */
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#define USE_GNU
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#include "strlenopt-31.c"
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/* { dg-final { scan-tree-dump-times "stpcpy \\(" 1 "strlen" } } */
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/* { dg-final { scan-tree-dump-times "memcpy \\(" 2 "strlen" } } */
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/* { dg-final { scan-tree-dump-not "strlen \\(" "strlen" } } */
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@ -61,7 +61,13 @@ struct strinfo
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tree length;
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/* Any of the corresponding pointers for querying alias oracle. */
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tree ptr;
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/* Statement for delayed length computation. */
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/* This is used for two things:
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- To record the statement that should be used for delayed length
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computations. We maintain the invariant that all related strinfos
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have delayed lengths or none do.
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- To record the malloc or calloc call that produced this result. */
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gimple *stmt;
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/* Pointer to '\0' if known, if NULL, it can be computed as
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ptr + length. */
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@ -156,6 +162,19 @@ get_strinfo (int idx)
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return (*stridx_to_strinfo)[idx];
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}
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/* Get the next strinfo in the chain after SI, or null if none. */
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static inline strinfo *
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get_next_strinfo (strinfo *si)
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{
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if (si->next == 0)
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return NULL;
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strinfo *nextsi = get_strinfo (si->next);
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if (nextsi == NULL || nextsi->first != si->first || nextsi->prev != si->idx)
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return NULL;
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return nextsi;
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}
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/* Helper function for get_stridx. */
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static int
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@ -438,6 +457,45 @@ set_strinfo (int idx, strinfo *si)
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(*stridx_to_strinfo)[idx] = si;
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}
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/* Return the first strinfo in the related strinfo chain
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if all strinfos in between belong to the chain, otherwise NULL. */
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static strinfo *
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verify_related_strinfos (strinfo *origsi)
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{
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strinfo *si = origsi, *psi;
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if (origsi->first == 0)
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return NULL;
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for (; si->prev; si = psi)
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{
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if (si->first != origsi->first)
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return NULL;
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psi = get_strinfo (si->prev);
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if (psi == NULL)
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return NULL;
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if (psi->next != si->idx)
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return NULL;
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}
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if (si->idx != si->first)
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return NULL;
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return si;
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}
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/* Set SI's endptr to ENDPTR and compute its length based on SI->ptr.
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Use LOC for folding. */
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static void
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set_endptr_and_length (location_t loc, strinfo *si, tree endptr)
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{
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si->endptr = endptr;
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si->stmt = NULL;
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tree start_as_size = fold_convert_loc (loc, size_type_node, si->ptr);
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tree end_as_size = fold_convert_loc (loc, size_type_node, endptr);
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si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node,
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end_as_size, start_as_size);
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}
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/* Return string length, or NULL if it can't be computed. */
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static tree
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case BUILT_IN_STPCPY_CHK_CHKP:
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gcc_assert (lhs != NULL_TREE);
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loc = gimple_location (stmt);
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si->endptr = lhs;
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si->stmt = NULL;
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lhs = fold_convert_loc (loc, size_type_node, lhs);
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si->length = fold_convert_loc (loc, size_type_node, si->ptr);
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si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node,
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lhs, si->length);
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set_endptr_and_length (loc, si, lhs);
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for (strinfo *chainsi = verify_related_strinfos (si);
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chainsi != NULL;
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chainsi = get_next_strinfo (chainsi))
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if (chainsi->length == NULL)
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set_endptr_and_length (loc, chainsi, lhs);
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break;
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case BUILT_IN_MALLOC:
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break;
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@ -607,32 +665,6 @@ unshare_strinfo (strinfo *si)
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return nsi;
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}
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/* Return first strinfo in the related strinfo chain
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if all strinfos in between belong to the chain, otherwise
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NULL. */
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static strinfo *
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verify_related_strinfos (strinfo *origsi)
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{
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strinfo *si = origsi, *psi;
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if (origsi->first == 0)
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return NULL;
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for (; si->prev; si = psi)
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{
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if (si->first != origsi->first)
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return NULL;
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psi = get_strinfo (si->prev);
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if (psi == NULL)
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return NULL;
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if (psi->next != si->idx)
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return NULL;
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}
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if (si->idx != si->first)
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return NULL;
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return si;
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}
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/* Attempt to create a new strinfo for BASESI + OFF, or find existing
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strinfo if there is any. Return it's idx, or 0 if no strinfo has
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been created. */
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