https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117271
Bug ID: 117271
Summary: [13/14/15 regression] GCC trunk emits larger code at
-Os than 12.4.0
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: dccitaliano at gmail dot com
Target Milestone: ---
Testcase (-Os):
int f(int* a) {
if (*a > 5 && ((*a % 2 == 0 && *a < 20) || (*a > 10 && *a % 3 != 0))) {
*a = *a * 2;
}
int arr[5];
for (int i = 0; i < 5; i++) {
arr[i] = *a + i;
}
for (int j = 0; j < 3; j++) {
for (int k = 0; k < 2 && arr[j] % 2 == 0; k++) {
arr[j] += k * 2;
}
}
int sum = 0;
for (int m = 0; m < 5 && (arr[m] % 3 == 0 || arr[m] > 10); m++) {
sum += arr[m] * (m % 2 == 0 ? 2 : 3);
for (int n = 0; n < 2 && (sum % 2 != 0 || m > 2); n++) {
sum -= n * (m % 2 == 0 ? 1 : 2);
if (n > 0 && sum > 10 && (arr[m] % 2 != 0 || m < 3)) {
sum += arr[m] / 2;
}
}
if (sum > 20 && m > 1) {
sum *= 2;
}
}
arr[0] += sum;
return arr[0];
}
Bisects to:
commit aadc5c07feb0ab08729ab25d0d896b55860ad9e6
Author: Andrew Pinski <[email protected]>
Date: Mon Aug 7 00:05:21 2023 -0700
VR-VALUES [PR28794]: optimize compare assignments also
This patch fixes the oldish (2006) bug where VRP was not
optimizing the comparison for assignments while handling
them for GIMPLE_COND only.
It just happens to also solves PR 103281 due to allowing
to optimize `c < 1` to `c == 0` and then we get
`(c == 0) == c` (which was handled by r14-2501-g285c9d04).
OK? Bootstrapped and tested on x86_64-linux-gnu with no
regressions.
PR tree-optimization/103281
PR tree-optimization/28794
gcc/ChangeLog:
* vr-values.cc
(simplify_using_ranges::simplify_cond_using_ranges_1): Split out
majority to ...
(simplify_using_ranges::simplify_compare_using_ranges_1): Here.
(simplify_using_ranges::simplify_casted_cond): Rename to ...
(simplify_using_ranges::simplify_casted_compare): This
and change arguments to take op0 and op1.
(simplify_using_ranges::simplify_compare_assign_using_ranges_1):
New method.
(simplify_using_ranges::simplify): For tcc_comparison assignments
call
simplify_compare_assign_using_ranges_1.
* vr-values.h (simplify_using_ranges): Add
new methods, simplify_compare_using_ranges_1 and
simplify_compare_assign_using_ranges_1.
Rename simplify_casted_cond and simplify_casted_compare and
update argument types.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/pr103281-1.c: New test.
* gcc.dg/tree-ssa/vrp-compare-1.c: New test.
gcc/testsuite/gcc.dg/tree-ssa/pr103281-1.c | 19 +++
gcc/testsuite/gcc.dg/tree-ssa/vrp-compare-1.c | 13 +++
gcc/vr-values.cc | 160 ++++++++++++++++----------
gcc/vr-values.h | 4 +-
4 files changed, 134 insertions(+), 62 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr103281-1.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/vrp-compare-1.c
