From 167ef0417008ac6fce811cc077afa116ecda395e Mon Sep 17 00:00:00 2001
From: Pavol Rusnak <pavol@rusnak.io>
Date: Sun, 13 Apr 2025 14:34:48 +0200
Subject: [PATCH] gcc14: fix internal compiler error on aarch64

- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118501
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118892
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119133
---
 .../patches/14/aarch64-fix-ice-subreg.patch   | 87 +++++++++++++++++++
 .../compilers/gcc/patches/default.nix         |  5 ++
 2 files changed, 92 insertions(+)
 create mode 100644 pkgs/development/compilers/gcc/patches/14/aarch64-fix-ice-subreg.patch

diff --git a/pkgs/development/compilers/gcc/patches/14/aarch64-fix-ice-subreg.patch b/pkgs/development/compilers/gcc/patches/14/aarch64-fix-ice-subreg.patch
new file mode 100644
index 000000000000..a8783ddbfa27
--- /dev/null
+++ b/pkgs/development/compilers/gcc/patches/14/aarch64-fix-ice-subreg.patch
@@ -0,0 +1,87 @@
+diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
+index d3c381e82ce..6a481059bf0 100644
+--- a/gcc/config/aarch64/aarch64.md
++++ b/gcc/config/aarch64/aarch64.md
+@@ -6161,8 +6161,8 @@
+ 			  (match_dup 1))
+ 	(match_dup 2))]
+   {
+-    operands[2] = lowpart_subreg (<GPI:MODE>mode, operands[2],
+-				  <ALLX:MODE>mode);
++    operands[2] = force_lowpart_subreg (<GPI:MODE>mode, operands[2],
++					<ALLX:MODE>mode);
+   }
+   [(set_attr "type" "bfm,neon_ins_q,neon_ins_q")
+    (set_attr "arch" "*,simd,simd")]
+@@ -7210,7 +7210,7 @@
+ 
+       emit_insn (gen_iorv2<v_int_equiv>3 (
+ 	lowpart_subreg (V2<V_INT_EQUIV>mode, operands[0], <MODE>mode),
+-	lowpart_subreg (V2<V_INT_EQUIV>mode, operands[1], <MODE>mode),
++	force_lowpart_subreg (V2<V_INT_EQUIV>mode, operands[1], <MODE>mode),
+ 	v_bitmask));
+       DONE;
+     }
+@@ -7255,8 +7255,8 @@
+   "TARGET_SIMD"
+ {
+   rtx tmp = gen_reg_rtx (<VCONQ>mode);
+-  rtx op1 = lowpart_subreg (<VCONQ>mode, operands[1], <MODE>mode);
+-  rtx op2 = lowpart_subreg (<VCONQ>mode, operands[2], <MODE>mode);
++  rtx op1 = force_lowpart_subreg (<VCONQ>mode, operands[1], <MODE>mode);
++  rtx op2 = force_lowpart_subreg (<VCONQ>mode, operands[2], <MODE>mode);
+   emit_insn (gen_xorsign3 (<VCONQ>mode, tmp, op1, op2));
+   emit_move_insn (operands[0],
+ 		  lowpart_subreg (<MODE>mode, tmp, <VCONQ>mode));
+diff --git a/gcc/explow.cc b/gcc/explow.cc
+index f6843398c4b..80f59418bca 100644
+--- a/gcc/explow.cc
++++ b/gcc/explow.cc
+@@ -760,6 +760,34 @@ force_subreg (machine_mode outermode, rtx op,
+   return simplify_gen_subreg (outermode, op, innermode, byte);
+ }
+ 
++/* Try to return an rvalue expression for the OUTERMODE lowpart of OP,
++   which has mode INNERMODE.  Allow OP to be forced into a new register
++   if necessary.
++
++   Return null on failure.  */
++
++rtx
++force_lowpart_subreg (machine_mode outermode, rtx op,
++		      machine_mode innermode)
++{
++  auto byte = subreg_lowpart_offset (outermode, innermode);
++  return force_subreg (outermode, op, innermode, byte);
++}
++
++/* Try to return an rvalue expression for the OUTERMODE highpart of OP,
++   which has mode INNERMODE.  Allow OP to be forced into a new register
++   if necessary.
++
++   Return null on failure.  */
++
++rtx
++force_highpart_subreg (machine_mode outermode, rtx op,
++		       machine_mode innermode)
++{
++  auto byte = subreg_highpart_offset (outermode, innermode);
++  return force_subreg (outermode, op, innermode, byte);
++}
++
+ /* If X is a memory ref, copy its contents to a new temp reg and return
+    that reg.  Otherwise, return X.  */
+ 
+diff --git a/gcc/explow.h b/gcc/explow.h
+index cbd1fcb7eb3..de89e9e2933 100644
+--- a/gcc/explow.h
++++ b/gcc/explow.h
+@@ -43,6 +43,8 @@ extern rtx copy_to_suggested_reg (rtx, rtx, machine_mode);
+ extern rtx force_reg (machine_mode, rtx);
+ 
+ extern rtx force_subreg (machine_mode, rtx, machine_mode, poly_uint64);
++extern rtx force_lowpart_subreg (machine_mode, rtx, machine_mode);
++extern rtx force_highpart_subreg (machine_mode, rtx, machine_mode);
+ 
+ /* Return given rtx, copied into a new temp reg if it was in memory.  */
+ extern rtx force_not_mem (rtx);
diff --git a/pkgs/development/compilers/gcc/patches/default.nix b/pkgs/development/compilers/gcc/patches/default.nix
index 7adc06b35779..598c42a48d3e 100644
--- a/pkgs/development/compilers/gcc/patches/default.nix
+++ b/pkgs/development/compilers/gcc/patches/default.nix
@@ -94,6 +94,11 @@ in
 ++ optional langD ./libphobos.patch
 ++ optional (!atLeast14) ./cfi_startproc-reorder-label-09-1.diff
 ++ optional (atLeast14 && !canApplyIainsDarwinPatches) ./cfi_startproc-reorder-label-14-1.diff
+# backports of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118501
+#          and https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118892
+#          and https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119133
+# (hopefully all three will be included in the upcoming 14.3.0 release)
+++ optional is14 ./14/aarch64-fix-ice-subreg.patch
 
 ## 2. Patches relevant to gcc>=12 on specific platforms ####################################