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| author | Jakub Jelinek <jakub@redhat.com> | 2024-03-27 19:38:06 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2024-03-27 19:39:18 +0100 |
| commit | 4b0443361a82ef89d519c9ae6d4d3bec74376e8f (patch) | |
| tree | 06bff8c7c340d074628fbf9550c2d52b07450642 /gcc/c-family | |
| parent | f85d3362cdb4bab611508dd9a38d9015c02ff7ca (diff) | |
| download | gcc-4b0443361a82ef89d519c9ae6d4d3bec74376e8f.zip gcc-4b0443361a82ef89d519c9ae6d4d3bec74376e8f.tar.gz gcc-4b0443361a82ef89d519c9ae6d4d3bec74376e8f.tar.bz2 | |
c-family: Cast __atomic_load_*/__atomic_exchange_* result to _BitInt rather then VCE it [PR114469]
As written in the PR, torture/bitint-64.c test fails with -O2 -flto
and the reason is that on _BitInt arches where the padding bits
are undefined, the padding bits in the _Atomic vars are also undefined,
but when __atomic_load or __atomic_exchange on a _BitInt _Atomic variable
with some padding bits is lowered into __atomic_load_{1,2,4,8,16} or
__atomic_exchange_*, the mode precision unsigned result is VIEW_CONVERT_EXPR
converted to _BitInt and because of the VCE nothing actually sign/zero
extends it as needed for later uses - the var is no longer addressable and
expansion assumes such automatic vars are properly extended.
The following patch fixes that by using NOP_EXPR on it (the
VIEW_CONVERT_EXPR after it will then be optimized away during
gimplification, didn't want to repeat it in the code as else result = build1
(VIEW_CONVERT_EXPR, ...); twice.
2024-03-27 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/114469
* c-common.cc (resolve_overloaded_builtin): For _BitInt result
on !extended targets convert result to the _BitInt type before
using VIEW_CONVERT_EXPR.
Diffstat (limited to 'gcc/c-family')
| -rw-r--r-- | gcc/c-family/c-common.cc | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc index 48844b1..6fa8243 100644 --- a/gcc/c-family/c-common.cc +++ b/gcc/c-family/c-common.cc @@ -8461,7 +8461,19 @@ resolve_overloaded_builtin (location_t loc, tree function, if (new_return) { /* Cast function result from I{1,2,4,8,16} to the required type. */ - result = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (new_return), result); + if (TREE_CODE (TREE_TYPE (new_return)) == BITINT_TYPE) + { + struct bitint_info info; + unsigned prec = TYPE_PRECISION (TREE_TYPE (new_return)); + targetm.c.bitint_type_info (prec, &info); + if (!info.extended) + /* For _BitInt which has the padding bits undefined + convert to the _BitInt type rather than VCE to force + zero or sign extension. */ + result = build1 (NOP_EXPR, TREE_TYPE (new_return), result); + } + result + = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (new_return), result); result = build2 (MODIFY_EXPR, TREE_TYPE (new_return), new_return, result); TREE_SIDE_EFFECTS (result) = 1; |