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| author | Jakub Jelinek <jakub@redhat.com> | 2020-04-23 21:11:36 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-04-23 21:11:36 +0200 |
| commit | bca558de2a24b2a78c6a321d6cec384e07759d77 (patch) | |
| tree | 001650ca80858285d7089a14cb14d6787412a3fd /gcc/tree.c | |
| parent | 06eca1acafa27e19e82dc73927394a7a4d0bdbc5 (diff) | |
| download | gcc-bca558de2a24b2a78c6a321d6cec384e07759d77.zip gcc-bca558de2a24b2a78c6a321d6cec384e07759d77.tar.gz gcc-bca558de2a24b2a78c6a321d6cec384e07759d77.tar.bz2 | |
tree: Fix up get_narrower [PR94724]
In the recent get_narrower change, I wanted it to be efficient and avoid
recursion if there are many nested COMPOUND_EXPRs. That builds the
COMPOUND_EXPR nest with the right arguments, but as build2_loc computes some
flags like TREE_SIDE_EFFECTS, TREE_CONSTANT and TREE_READONLY, when it
is called with something that will not be the argument in the end, those
flags are computed incorrectly.
So, this patch instead uses an auto_vec and builds them in the reverse order
so when they are built, they are built with the correct operands.
2020-04-23 Jakub Jelinek <jakub@redhat.com>
PR middle-end/94724
* tree.c (get_narrower): Instead of creating COMPOUND_EXPRs
temporarily with non-final second operand and updating it later,
push COMPOUND_EXPRs into a vector and process it in reverse,
creating COMPOUND_EXPRs with the final operands.
* gcc.c-torture/execute/pr94724.c: New test.
Diffstat (limited to 'gcc/tree.c')
| -rw-r--r-- | gcc/tree.c | 20 |
1 files changed, 12 insertions, 8 deletions
@@ -8881,18 +8881,22 @@ get_narrower (tree op, int *unsignedp_ptr) if (TREE_CODE (op) == COMPOUND_EXPR) { - while (TREE_CODE (op) == COMPOUND_EXPR) + do op = TREE_OPERAND (op, 1); + while (TREE_CODE (op) == COMPOUND_EXPR); tree ret = get_narrower (op, unsignedp_ptr); if (ret == op) return win; - op = win; - for (tree *p = &win; TREE_CODE (op) == COMPOUND_EXPR; - op = TREE_OPERAND (op, 1), p = &TREE_OPERAND (*p, 1)) - *p = build2_loc (EXPR_LOCATION (op), COMPOUND_EXPR, - TREE_TYPE (ret), TREE_OPERAND (op, 0), - ret); - return win; + auto_vec <tree, 16> v; + unsigned int i; + for (tree op = win; TREE_CODE (op) == COMPOUND_EXPR; + op = TREE_OPERAND (op, 1)) + v.safe_push (op); + FOR_EACH_VEC_ELT_REVERSE (v, i, op) + ret = build2_loc (EXPR_LOCATION (op), COMPOUND_EXPR, + TREE_TYPE (win), TREE_OPERAND (op, 0), + ret); + return ret; } while (TREE_CODE (op) == NOP_EXPR) { |