commit: 5c4e50d6f18794b3bece70beadb05d256087f45d Author: Sam James <sam <AT> gentoo <DOT> org> AuthorDate: Tue Jan 14 16:22:17 2025 +0000 Commit: Sam James <sam <AT> gentoo <DOT> org> CommitDate: Tue Jan 14 16:22:17 2025 +0000 URL: https://gitweb.gentoo.org/proj/gcc-patches.git/commit/?id=5c4e50d6
15.0.0: drop upstream ifcombine patch Merged upstream. Signed-off-by: Sam James <sam <AT> gentoo.org> ...xtend-constants-to-compare-with-bitfields.patch | 214 --------------------- 15.0.0/gentoo/README.history | 1 + 2 files changed, 1 insertion(+), 214 deletions(-) diff --git a/15.0.0/gentoo/84_all_PR118456-check-and-extend-constants-to-compare-with-bitfields.patch b/15.0.0/gentoo/84_all_PR118456-check-and-extend-constants-to-compare-with-bitfields.patch deleted file mode 100644 index e005c02..0000000 --- a/15.0.0/gentoo/84_all_PR118456-check-and-extend-constants-to-compare-with-bitfields.patch +++ /dev/null @@ -1,214 +0,0 @@ -https://inbox.sourceware.org/gcc-patches/ora5bugmmi....@lxoliva.fsfla.org/ - -From 4e794a3a5de8e8fa0fcaf98e5ea298d4a3c71192 Mon Sep 17 00:00:00 2001 -Message-ID: <4e794a3a5de8e8fa0fcaf98e5ea298d4a3c71192.1736844127.git....@gentoo.org> -From: Alexandre Oliva <ol...@adacore.com> -Date: Mon, 13 Jan 2025 23:22:45 -0300 -Subject: [PATCH 1/2] check and extend constants to compare with bitfields - [PR118456] - -Add logic to check and extend constants compared with bitfields, so -that fields are only compared with constants they could actually -equal. This involves making sure the signedness doesn't change -between loads and conversions before shifts: we'd need to carry a lot -more data to deal with all the possibilities. - -Regstrapped on x86_64-linux-gnu. Ok to install? - -for gcc/ChangeLog - - PR tree-optimization/118456 - * gimple-fold.cc (decode_field_reference): Punt if shifting - after changing signedness. - (fold_truth_andor_for_ifcombine): Check extension bits in - constants before clipping. - -for gcc/testsuite/ChangeLog - -PR tree-optimization/118456 - * gcc.dg/field-merge-21.c: New. - * gcc.dg/field-merge-22.c: New. ---- - gcc/gimple-fold.cc | 40 +++++++++++++++++++- - gcc/testsuite/gcc.dg/field-merge-21.c | 53 +++++++++++++++++++++++++++ - gcc/testsuite/gcc.dg/field-merge-22.c | 31 ++++++++++++++++ - 3 files changed, 122 insertions(+), 2 deletions(-) - create mode 100644 gcc/testsuite/gcc.dg/field-merge-21.c - create mode 100644 gcc/testsuite/gcc.dg/field-merge-22.c - -diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc -index 93ed8b3abb05..5b1fbe6db1df 100644 ---- a/gcc/gimple-fold.cc -+++ b/gcc/gimple-fold.cc -@@ -7712,6 +7712,18 @@ decode_field_reference (tree *pexp, HOST_WIDE_INT *pbitsize, - - if (shiftrt) - { -+ /* Punt if we're shifting by more than the loaded bitfield (after -+ adjustment), or if there's a shift after a change of signedness, punt. -+ When comparing this field with a constant, we'll check that the -+ constant is a proper sign- or zero-extension (depending on signedness) -+ of a value that would fit in the selected portion of the bitfield. A -+ shift after a change of signedness would make the extension -+ non-uniform, and we can't deal with that (yet ???). See -+ gcc.dg/field-merge-22.c for a test that would go wrong. */ -+ if (*pbitsize <= shiftrt -+ || (convert_before_shift -+ && outer_type && unsignedp != TYPE_UNSIGNED (outer_type))) -+ return NULL_TREE; - if (!*preversep ? !BYTES_BIG_ENDIAN : BYTES_BIG_ENDIAN) - *pbitpos += shiftrt; - *pbitsize -= shiftrt; -@@ -8512,13 +8524,25 @@ fold_truth_andor_for_ifcombine (enum tree_code code, tree truth_type, - and bit position. */ - if (l_const.get_precision ()) - { -+ /* Before clipping upper bits of the right-hand operand of the compare, -+ check that they're sign or zero extensions, depending on how the -+ left-hand operand would be extended. */ -+ bool l_non_ext_bits = false; -+ if (ll_bitsize < lr_bitsize) -+ { -+ wide_int zext = wi::zext (l_const, ll_bitsize); -+ if ((ll_unsignedp ? zext : wi::sext (l_const, ll_bitsize)) == l_const) -+ l_const = zext; -+ else -+ l_non_ext_bits = true; -+ } - /* We're doing bitwise equality tests, so don't bother with sign - extensions. */ - l_const = wide_int::from (l_const, lnprec, UNSIGNED); - if (ll_and_mask.get_precision ()) - l_const &= wide_int::from (ll_and_mask, lnprec, UNSIGNED); - l_const <<= xll_bitpos; -- if ((l_const & ~ll_mask) != 0) -+ if (l_non_ext_bits || (l_const & ~ll_mask) != 0) - { - warning_at (lloc, OPT_Wtautological_compare, - "comparison is always %d", wanted_code == NE_EXPR); -@@ -8530,11 +8554,23 @@ fold_truth_andor_for_ifcombine (enum tree_code code, tree truth_type, - again. */ - gcc_checking_assert (r_const.get_precision ()); - -+ /* Before clipping upper bits of the right-hand operand of the compare, -+ check that they're sign or zero extensions, depending on how the -+ left-hand operand would be extended. */ -+ bool r_non_ext_bits = false; -+ if (rl_bitsize < rr_bitsize) -+ { -+ wide_int zext = wi::zext (r_const, rl_bitsize); -+ if ((rl_unsignedp ? zext : wi::sext (r_const, rl_bitsize)) == r_const) -+ r_const = zext; -+ else -+ r_non_ext_bits = true; -+ } - r_const = wide_int::from (r_const, lnprec, UNSIGNED); - if (rl_and_mask.get_precision ()) - r_const &= wide_int::from (rl_and_mask, lnprec, UNSIGNED); - r_const <<= xrl_bitpos; -- if ((r_const & ~rl_mask) != 0) -+ if (r_non_ext_bits || (r_const & ~rl_mask) != 0) - { - warning_at (rloc, OPT_Wtautological_compare, - "comparison is always %d", wanted_code == NE_EXPR); -diff --git a/gcc/testsuite/gcc.dg/field-merge-21.c b/gcc/testsuite/gcc.dg/field-merge-21.c -new file mode 100644 -index 000000000000..042b2123eb63 ---- /dev/null -+++ b/gcc/testsuite/gcc.dg/field-merge-21.c -@@ -0,0 +1,53 @@ -+/* { dg-do run } */ -+/* { dg-options "-O2" } */ -+ -+/* PR tree-optimization/118456 */ -+/* Check that shifted fields compared with a constants compare correctly even -+ if the constant contains sign-extension bits not present in the bit -+ range. */ -+ -+struct S { unsigned long long o; unsigned short a, b; } s; -+ -+__attribute__((noipa)) int -+foo (void) -+{ -+ return ((unsigned char) s.a) >> 3 == 17 && ((signed char) s.b) >> 2 == -27; -+} -+ -+__attribute__((noipa)) int -+bar (void) -+{ -+ return ((unsigned char) s.a) >> 3 == 17 && ((signed char) s.b) >> 2 == -91; -+} -+ -+__attribute__((noipa)) int -+bars (void) -+{ -+ return ((unsigned char) s.a) >> 3 == 17 && ((signed char) s.b) >> 2 == 37; -+} -+ -+__attribute__((noipa)) int -+baz (void) -+{ -+ return ((unsigned char) s.a) >> 3 == 49 && ((signed char) s.b) >> 2 == -27; -+} -+ -+__attribute__((noipa)) int -+bazs (void) -+{ -+ return ((unsigned char) s.a) >> 3 == (unsigned char) -15 && ((signed char) s.b) >> 2 == -27; -+} -+ -+int -+main () -+{ -+ s.a = 17 << 3; -+ s.b = (unsigned short)(-27u << 2); -+ if (foo () != 1 -+ || bar () != 0 -+ || bars () != 0 -+ || baz () != 0 -+ || bazs () != 0) -+ __builtin_abort (); -+ return 0; -+} -diff --git a/gcc/testsuite/gcc.dg/field-merge-22.c b/gcc/testsuite/gcc.dg/field-merge-22.c -new file mode 100644 -index 000000000000..45b29c0bccaf ---- /dev/null -+++ b/gcc/testsuite/gcc.dg/field-merge-22.c -@@ -0,0 +1,31 @@ -+/* { dg-do run } */ -+/* { dg-options "-O2" } */ -+ -+/* PR tree-optimization/118456 */ -+/* Check that compares with constants take into account sign/zero extension of -+ both the bitfield and of the shifting type. */ -+ -+#define shift (__CHAR_BIT__ - 4) -+ -+struct S { -+ signed char a : shift + 2; -+ signed char b : shift + 2; -+ short ignore[0]; -+} s; -+ -+__attribute__((noipa)) int -+foo (void) -+{ -+ return ((unsigned char) s.a) >> shift == 15 -+ && ((unsigned char) s.b) >> shift == 0; -+} -+ -+int -+main () -+{ -+ s.a = -1; -+ s.b = 1; -+ if (foo () != 1) -+ __builtin_abort (); -+ return 0; -+} - -base-commit: 31c3c1a83fd885b4687c9f6f7acd68af76d758d3 --- -2.48.0 - diff --git a/15.0.0/gentoo/README.history b/15.0.0/gentoo/README.history index 0607277..02c646e 100644 --- a/15.0.0/gentoo/README.history +++ b/15.0.0/gentoo/README.history @@ -1,5 +1,6 @@ 41 ???? + - 84_all_PR118456-check-and-extend-constants-to-compare-with-bitfields.patch - 86_all_PR118418-Fix-build-for-STORE_FLAG_VALUE-0-targets.patch 40 14 January 2025
