gcc: Fix fma steering segfault due to on aarch64

Seen with opengl-es-cts compilation for qemuarm64

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/recipes-devtools/gcc/gcc-15.1.inc b/meta/recipes-devtools/gcc/gcc-15.1.inc
index af29db8e5b8b7f99371be01f5f64275e685c3ebd..25688aab346c6b6f696a2c7ba5dc3cc5f3c09800 100644 (file)
--- a/meta/recipes-devtools/gcc/gcc-15.1.inc
+++ b/meta/recipes-devtools/gcc/gcc-15.1.inc
@@ -73,6 +73,7 @@ SRC_URI = "${BASEURI} \
            file://0025-gcc-testsuite-tweaks-for-mips-OE.patch \
            file://0026-arm-fully-validate-mem_noofs_operand-PR120351.patch \
            file://0026-fix-incorrect-preprocessor-line-numbers.patch \
+           file://0027-aarch64-Fix-fma-steering-when-rename-fails-PR120119.patch \
 "
 
 UNPACKDIR = "${TMPDIR}/work-shared/gcc-${PV}-${PR}/sources"

diff --git a/meta/recipes-devtools/gcc/gcc/0027-aarch64-Fix-fma-steering-when-rename-fails-PR120119.patch b/meta/recipes-devtools/gcc/gcc/0027-aarch64-Fix-fma-steering-when-rename-fails-PR120119.patch
new file mode 100644 (file)
index 0000000..a59cb45
--- /dev/null
+++ b/meta/recipes-devtools/gcc/gcc/0027-aarch64-Fix-fma-steering-when-rename-fails-PR120119.patch
@@ -0,0 +1,69 @@
+From b28d5f51e1ec75f6878593ef084e9cfb836b9db4 Mon Sep 17 00:00:00 2001
+From: Andrew Pinski <quic_apinski@quicinc.com>
+Date: Tue, 22 Jul 2025 10:32:42 -0700
+Subject: [PATCH] aarch64: Fix fma steering when rename fails [PR120119]
+
+Regrename can fail in some case and `insn_rr[INSN_UID (insn)].op_info`
+will be null. The FMA steering code was not expecting the failure to happen.
+This started to happen after early RA was added but it has been a latent bug
+before that.
+
+Build and tested for aarch64-linux-gnu.
+
+       PR target/120119
+
+gcc/ChangeLog:
+
+       * config/aarch64/cortex-a57-fma-steering.cc (func_fma_steering::analyze):
+       Skip if renaming fails.
+
+gcc/testsuite/ChangeLog:
+
+       * g++.dg/torture/pr120119-1.C: New test.
+
+Upstream-Status: Submitted [https://gcc.gnu.org/pipermail/gcc-patches/2025-July/690239.html]
+Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ gcc/config/aarch64/cortex-a57-fma-steering.cc |  5 +++++
+ gcc/testsuite/g++.dg/torture/pr120119-1.C     | 15 +++++++++++++++
+ 2 files changed, 20 insertions(+)
+ create mode 100644 gcc/testsuite/g++.dg/torture/pr120119-1.C
+
+diff --git a/gcc/config/aarch64/cortex-a57-fma-steering.cc b/gcc/config/aarch64/cortex-a57-fma-steering.cc
+index fd6da66d855..f7675bed13d 100644
+--- a/gcc/config/aarch64/cortex-a57-fma-steering.cc
++++ b/gcc/config/aarch64/cortex-a57-fma-steering.cc
+@@ -948,6 +948,11 @@ func_fma_steering::analyze ()
+ 
+         /* Search the chain where this instruction is (one of) the root.  */
+         dest_op_info = insn_rr[INSN_UID (insn)].op_info;
++
++        /* Register rename could fail. */
++        if (!dest_op_info)
++          continue;
++
+         dest_regno = REGNO (SET_DEST (PATTERN (insn)));
+         for (i = 0; i < dest_op_info->n_chains; i++)
+           {
+diff --git a/gcc/testsuite/g++.dg/torture/pr120119-1.C b/gcc/testsuite/g++.dg/torture/pr120119-1.C
+new file mode 100644
+index 00000000000..1206feb310b
+--- /dev/null
++++ b/gcc/testsuite/g++.dg/torture/pr120119-1.C
+@@ -0,0 +1,15 @@
++// { dg-do compile }
++// { dg-additional-options "-mcpu=cortex-a57" { target aarch64*-*-* } }
++
++// PR target/120119
++
++struct a {
++  float operator()(int b, int c) { return d[c * 4 + b]; }
++  float *d;
++};
++float e(float *);
++auto f(a b) {
++  float g[]{b(1, 1), b(2, 1), b(3, 1), b(1, 2), b(2, 2), b(3, 2), b(1, 3),
++            b(2, 3), b(3, 3), b(3, 2), b(1, 3), b(2, 3), b(3, 3)};
++  return b.d[0] * e(g);
++}