commit:     c18d0e4be5597665342d4b16f228cfe4dff9f5b0
Author:     Sam James <sam <AT> gentoo <DOT> org>
AuthorDate: Mon Mar  4 23:33:51 2024 +0000
Commit:     Sam James <sam <AT> gentoo <DOT> org>
CommitDate: Mon Mar  4 23:34:12 2024 +0000
URL:        https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=c18d0e4b

sys-devel/gcc: backport uninit var fix to 14.0.1_pre20240303

Signed-off-by: Sam James <sam <AT> gentoo.org>

 .../gcc/files/gcc-14.0.1_pre20240303-uninit.patch  | 48 ++++++++++++++++++++++
 ...303.ebuild => gcc-14.0.1_pre20240303-r1.ebuild} |  1 +
 2 files changed, 49 insertions(+)

diff --git a/sys-devel/gcc/files/gcc-14.0.1_pre20240303-uninit.patch 
b/sys-devel/gcc/files/gcc-14.0.1_pre20240303-uninit.patch
new file mode 100644
index 000000000000..5ad41c4581a9
--- /dev/null
+++ b/sys-devel/gcc/files/gcc-14.0.1_pre20240303-uninit.patch
@@ -0,0 +1,48 @@
+https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=901e7bdab70e2275723ac31dacbbce0b6f68f4f4
+
+From 901e7bdab70e2275723ac31dacbbce0b6f68f4f4 Mon Sep 17 00:00:00 2001
+From: Jakub Jelinek <[email protected]>
+Date: Mon, 4 Mar 2024 19:23:02 +0100
+Subject: [PATCH] combine: Fix recent WORD_REGISTER_OPERATIONS check [PR113010]
+
+On Mon, Mar 04, 2024 at 05:18:39PM +0100, Rainer Orth wrote:
+> unfortunately, the patch broke Solaris/SPARC bootstrap
+> (sparc-sun-solaris2.11):
+>
+> .../gcc/combine.cc: In function 'rtx_code simplify_comparison(rtx_code, 
rtx_def**, rtx_def**)':
+> .../gcc/combine.cc:12101:25: error: '*(unsigned int*)((char*)&inner_mode + 
offsetof(scalar_int_mode, scalar_int_mode::m_mode))' may be used uninitialized 
[-Werror=maybe-uninitialized]
+> 12101 |   scalar_int_mode mode, inner_mode, tmode;
+>       |                         ^~~~~~~~~~
+
+I don't see how it could ever work properly, inner_mode in that spot is
+just uninitialized.
+
+I think we shouldn't worry about paradoxical subregs of non-scalar_int_mode
+REGs/MEMs and for the scalar_int_mode ones should initialize inner_mode
+before we use it.
+Another option would be to use
+maybe_lt (GET_MODE_PRECISION (GET_MODE (SUBREG_REG (op0))), BITS_PER_WORD)
+and
+load_extend_op (GET_MODE (SUBREG_REG (op0))) == ZERO_EXTEND,
+or set machine_mode smode = GET_MODE (SUBREG_REG (op0)); and use it in
+those two spots.
+
+2024-03-04  Jakub Jelinek  <[email protected]>
+
+       PR rtl-optimization/113010
+       * combine.cc (simplify_comparison): Guard the
+       WORD_REGISTER_OPERATIONS check on scalar_int_mode of SUBREG_REG
+       and initialize inner_mode.
+--- a/gcc/combine.cc
++++ b/gcc/combine.cc
+@@ -12554,6 +12554,8 @@ simplify_comparison (enum rtx_code code, rtx *pop0, 
rtx *pop1)
+         if (paradoxical_subreg_p (op0))
+           {
+             if (WORD_REGISTER_OPERATIONS
++                && is_a <scalar_int_mode> (GET_MODE (SUBREG_REG (op0)),
++                                           &inner_mode)
+                 && GET_MODE_PRECISION (inner_mode) < BITS_PER_WORD
+                 /* On WORD_REGISTER_OPERATIONS targets the bits
+                    beyond sub_mode aren't considered undefined,
+-- 
+2.39.3

diff --git a/sys-devel/gcc/gcc-14.0.1_pre20240303.ebuild 
b/sys-devel/gcc/gcc-14.0.1_pre20240303-r1.ebuild
similarity index 97%
rename from sys-devel/gcc/gcc-14.0.1_pre20240303.ebuild
rename to sys-devel/gcc/gcc-14.0.1_pre20240303-r1.ebuild
index 97b3b7629c95..ddfe33a42323 100644
--- a/sys-devel/gcc/gcc-14.0.1_pre20240303.ebuild
+++ b/sys-devel/gcc/gcc-14.0.1_pre20240303-r1.ebuild
@@ -60,5 +60,6 @@ src_prepare() {
 
        toolchain_src_prepare
 
+       eapply "${FILESDIR}"/${P}-uninit.patch
        eapply_user
 }

Reply via email to