From c95a9f1ee7ebd461cbced455271a993bae3a42b6 Mon Sep 17 00:00:00 2001 From: Alexandre Oliva Date: Wed, 15 Dec 2021 02:22:33 -0300 Subject: [PATCH] [PR100843] store by mult pieces: punt on max_len < min_len The testcase confuses the code that detects min and max len for the memset, so max_len ends up less than min_len. That shouldn't be possible, but the testcase requires us to handle this case. The store-by-mult-pieces algorithm actually relies on min and max lengths, so if we find them to be inconsistent, the best we can do is punting. for gcc/ChangeLog PR middle-end/100843 * builtins.c (try_store_by_multiple_pieces): Fail if min_len is greater than max_len. for gcc/testsuite/ChangeLog PR middle-end/100843 * gcc.dg/pr100843.c: New. --- gcc/builtins.c | 3 ++- gcc/testsuite/gcc.dg/pr100843.c | 8 ++++++++ 2 files changed, 10 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/pr100843.c diff --git a/gcc/builtins.c b/gcc/builtins.c index 03829c0..304d87d 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -3963,7 +3963,8 @@ try_store_by_multiple_pieces (rtx to, rtx len, unsigned int ctz_len, else if (max_len == min_len) blksize = max_len; else - gcc_unreachable (); + /* Huh, max_len < min_len? Punt. See pr100843.c. */ + return false; if (min_len >= blksize) { min_len -= blksize; diff --git a/gcc/testsuite/gcc.dg/pr100843.c b/gcc/testsuite/gcc.dg/pr100843.c new file mode 100644 index 0000000..695a2ec --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr100843.c @@ -0,0 +1,8 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -w" } */ + +char c; +void *memset(); +void test_integer_conversion_memset(void *d) { + memset(d, '\0', c); +} -- 2.7.4