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author | rsandifo <rsandifo@138bc75d-0d04-0410-961f-82ee72b054a4> | 2017-08-01 12:22:03 +0000 |
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committer | rsandifo <rsandifo@138bc75d-0d04-0410-961f-82ee72b054a4> | 2017-08-01 12:22:03 +0000 |
commit | 009baa50551b51d4f9a8a1a826f7a85f7761ee4e (patch) | |
tree | 1fefbf03dbf7561785c69b8142baef48ca052a8e | |
parent | 1c6e4932ee0cd58c3f3671549af55df7a35c8786 (diff) | |
download | gcc-009baa50551b51d4f9a8a1a826f7a85f7761ee4e.tar.gz |
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.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-7-branch@250772 138bc75d-0d04-0410-961f-82ee72b054a4
-rw-r--r-- | gcc/ChangeLog | 12 | ||||
-rw-r--r-- | gcc/testsuite/ChangeLog | 6 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/strlenopt-31.c | 25 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/strlenopt-31g.c | 9 | ||||
-rw-r--r-- | gcc/tree-ssa-strlen.c | 98 |
5 files changed, 117 insertions, 33 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d1403195e63..6b99b453811 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,15 @@ +2017-08-01 Richard Sandiford <richard.sandiford@linaro.org> + + 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. + 2017-08-01 Jakub Jelinek <jakub@redhat.com> PR tree-optimization/81588 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index ace54311caa..2477ff175f8 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2017-08-01 Richard Sandiford <richard.sandiford@linaro.org> + + PR tree-optimization/80769 + * gcc.dg/strlenopt-31.c: New test. + * gcc.dg/strlenopt-31g.c: Likewise. + 2017-08-01 Jakub Jelinek <jakub@redhat.com> PR tree-optimization/81588 diff --git a/gcc/testsuite/gcc.dg/strlenopt-31.c b/gcc/testsuite/gcc.dg/strlenopt-31.c new file mode 100644 index 00000000000..bdd46ba0000 --- /dev/null +++ b/gcc/testsuite/gcc.dg/strlenopt-31.c @@ -0,0 +1,25 @@ +/* { dg-do run } */ +/* { dg-options "-O2" } */ + +#include "strlenopt.h" + +__attribute__((noinline, noclone)) int +bar (char *p1, const char *q) +{ + strcpy (p1, "abcde"); + char *p2 = strchr (p1, '\0'); + strcpy (p2, q); + char *p3 = strchr (p2, '\0'); + memcpy (p3, "x", 2); + return strlen (p1); +} + +int +main (void) +{ + char buffer[10]; + int res = bar (buffer, "foo"); + if (strcmp (buffer, "abcdefoox") != 0 || res != 9) + abort (); + return 0; +} diff --git a/gcc/testsuite/gcc.dg/strlenopt-31g.c b/gcc/testsuite/gcc.dg/strlenopt-31g.c new file mode 100644 index 00000000000..45cc29c1024 --- /dev/null +++ b/gcc/testsuite/gcc.dg/strlenopt-31g.c @@ -0,0 +1,9 @@ +/* { dg-do run { target *-*-linux* *-*-gnu* } } */ +/* { dg-options "-O2 -fdump-tree-strlen" } */ + +#define USE_GNU +#include "strlenopt-31.c" + +/* { dg-final { scan-tree-dump-times "stpcpy \\(" 1 "strlen" } } */ +/* { dg-final { scan-tree-dump-times "memcpy \\(" 2 "strlen" } } */ +/* { dg-final { scan-tree-dump-not "strlen \\(" "strlen" } } */ diff --git a/gcc/tree-ssa-strlen.c b/gcc/tree-ssa-strlen.c index 141115ed12b..9c72d122bbe 100644 --- a/gcc/tree-ssa-strlen.c +++ b/gcc/tree-ssa-strlen.c @@ -61,7 +61,13 @@ struct strinfo tree length; /* Any of the corresponding pointers for querying alias oracle. */ tree ptr; - /* Statement for delayed length computation. */ + /* This is used for two things: + + - To record the statement that should be used for delayed length + computations. We maintain the invariant that all related strinfos + have delayed lengths or none do. + + - To record the malloc or calloc call that produced this result. */ gimple *stmt; /* Pointer to '\0' if known, if NULL, it can be computed as ptr + length. */ @@ -156,6 +162,19 @@ get_strinfo (int idx) return (*stridx_to_strinfo)[idx]; } +/* Get the next strinfo in the chain after SI, or null if none. */ + +static inline strinfo * +get_next_strinfo (strinfo *si) +{ + if (si->next == 0) + return NULL; + strinfo *nextsi = get_strinfo (si->next); + if (nextsi == NULL || nextsi->first != si->first || nextsi->prev != si->idx) + return NULL; + return nextsi; +} + /* Helper function for get_stridx. */ static int @@ -438,6 +457,45 @@ set_strinfo (int idx, strinfo *si) (*stridx_to_strinfo)[idx] = si; } +/* Return the first strinfo in the related strinfo chain + if all strinfos in between belong to the chain, otherwise NULL. */ + +static strinfo * +verify_related_strinfos (strinfo *origsi) +{ + strinfo *si = origsi, *psi; + + if (origsi->first == 0) + return NULL; + for (; si->prev; si = psi) + { + if (si->first != origsi->first) + return NULL; + psi = get_strinfo (si->prev); + if (psi == NULL) + return NULL; + if (psi->next != si->idx) + return NULL; + } + if (si->idx != si->first) + return NULL; + return si; +} + +/* Set SI's endptr to ENDPTR and compute its length based on SI->ptr. + Use LOC for folding. */ + +static void +set_endptr_and_length (location_t loc, strinfo *si, tree endptr) +{ + si->endptr = endptr; + si->stmt = NULL; + tree start_as_size = fold_convert_loc (loc, size_type_node, si->ptr); + tree end_as_size = fold_convert_loc (loc, size_type_node, endptr); + si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node, + end_as_size, start_as_size); +} + /* Return string length, or NULL if it can't be computed. */ static tree @@ -533,12 +591,12 @@ get_string_length (strinfo *si) case BUILT_IN_STPCPY_CHK_CHKP: gcc_assert (lhs != NULL_TREE); loc = gimple_location (stmt); - si->endptr = lhs; - si->stmt = NULL; - lhs = fold_convert_loc (loc, size_type_node, lhs); - si->length = fold_convert_loc (loc, size_type_node, si->ptr); - si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node, - lhs, si->length); + set_endptr_and_length (loc, si, lhs); + for (strinfo *chainsi = verify_related_strinfos (si); + chainsi != NULL; + chainsi = get_next_strinfo (chainsi)) + if (chainsi->length == NULL) + set_endptr_and_length (loc, chainsi, lhs); break; case BUILT_IN_MALLOC: break; @@ -607,32 +665,6 @@ unshare_strinfo (strinfo *si) return nsi; } -/* Return first strinfo in the related strinfo chain - if all strinfos in between belong to the chain, otherwise - NULL. */ - -static strinfo * -verify_related_strinfos (strinfo *origsi) -{ - strinfo *si = origsi, *psi; - - if (origsi->first == 0) - return NULL; - for (; si->prev; si = psi) - { - if (si->first != origsi->first) - return NULL; - psi = get_strinfo (si->prev); - if (psi == NULL) - return NULL; - if (psi->next != si->idx) - return NULL; - } - if (si->idx != si->first) - return NULL; - return si; -} - /* Attempt to create a new strinfo for BASESI + OFF, or find existing strinfo if there is any. Return it's idx, or 0 if no strinfo has been created. */ |