From 4c141304a869524c909a6a9346b004cda47659fc Mon Sep 17 00:00:00 2001 From: Uros Bizjak Date: Sat, 25 Jul 2015 11:19:24 +0200 Subject: re PR target/66648 (incorrect memcpy expansion with unrolled_loop strategy at -O2) PR target/66648 * config/i386/i386.c (ix86_expand_set_or_movmem): Emit main loop execution guard when min_size is less than size_needed. testsuite/ChangeLog: PR target/66648 * gcc.target/i386/pr66648.c: New test. From-SVN: r226212 --- gcc/ChangeLog | 6 ++++++ gcc/config/i386/i386.c | 5 +++-- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.target/pr66648.c | 33 +++++++++++++++++++++++++++++++++ 4 files changed, 47 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.target/pr66648.c (limited to 'gcc') diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e70f931..60c4ade 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2015-07-25 Uros Bizjak + + PR target/66648 + * config/i386/i386.c (ix86_expand_set_or_movmem): Emit main loop + execution guard when min_size is less than size_needed. + 2015-07-25 Sebastian Pop * doc/install.texi: Document supported versions of ISL. diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 068cadf..21512c6 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -25113,7 +25113,8 @@ ix86_expand_set_or_movmem (rtx dst, rtx src, rtx count_exp, rtx val_exp, dst = change_address (dst, BLKmode, destreg); set_mem_align (dst, desired_align * BITS_PER_UNIT); epilogue_size_needed = 0; - if (need_zero_guard && !min_size) + if (need_zero_guard + && min_size < (unsigned HOST_WIDE_INT) size_needed) { /* It is possible that we copied enough so the main loop will not execute. */ @@ -25245,7 +25246,7 @@ ix86_expand_set_or_movmem (rtx dst, rtx src, rtx count_exp, rtx val_exp, max_size -= align_bytes; } if (need_zero_guard - && !min_size + && min_size < (unsigned HOST_WIDE_INT) size_needed && (count < (unsigned HOST_WIDE_INT) size_needed || (align_bytes == 0 && count < ((unsigned HOST_WIDE_INT) size_needed diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index f832fb1..55e4cb0 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2015-07-25 Uros Bizjak + + PR target/66648 + * gcc.target/i386/pr66648.c: New test. + 2015-07-25 Tom de Vries * gcc.dg/graphite/graphite.exp: Include uns-*.c files in diff --git a/gcc/testsuite/gcc.target/pr66648.c b/gcc/testsuite/gcc.target/pr66648.c new file mode 100644 index 0000000..88c126f --- /dev/null +++ b/gcc/testsuite/gcc.target/pr66648.c @@ -0,0 +1,33 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -mstringop-strategy=unrolled_loop -mtune=nocona" } */ + +#define PATTERN 0xdeadbeef +#define SIZE 32 + +struct S { int i; char str[SIZE]; int j; }; + +void __attribute__((noclone, noinline)) +my_memcpy (char *, const char *, unsigned int); + +void +my_memcpy (char *dst, const char *src, unsigned int len) +{ + if (len < 8) + __builtin_abort (); + + __builtin_memcpy (dst, src, len); +} + +int +main (void) +{ + const char str[SIZE]= "1234567890123456789012345678901"; + struct S *s = __builtin_malloc (sizeof (struct S)); + + s->j = PATTERN; + my_memcpy (s->str, str, SIZE); + if (s->j != PATTERN) + __builtin_abort (); + + return 0; +} -- cgit v1.1