From 9cd37a06965f1993f6e70ca3f10008d02f77334b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Tue, 7 Oct 2025 08:46:43 +0200
Subject: [PATCH] std.debug.Dwarf: use 66 as the (fake) MIPS PC register

32-63 conflict with the floating point registers. 64 and 65 are used for the
ac0 hi/lo registers.
---
 lib/std/debug/Dwarf.zig       | 2 +-
 lib/std/debug/cpu_context.zig | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/std/debug/Dwarf.zig b/lib/std/debug/Dwarf.zig
index a6ecd07b23..98d7addb32 100644
--- a/lib/std/debug/Dwarf.zig
+++ b/lib/std/debug/Dwarf.zig
@@ -1433,7 +1433,7 @@ pub fn ipRegNum(arch: std.Target.Cpu.Arch) ?u16 {
         .arm, .armeb, .thumb, .thumbeb => 15,
         .hexagon => 76,
         .loongarch32, .loongarch64 => 64,
-        .mips, .mipsel, .mips64, .mips64el => 37,
+        .mips, .mipsel, .mips64, .mips64el => 66,
         .powerpc, .powerpcle, .powerpc64, .powerpc64le => 67,
         .riscv32, .riscv32be, .riscv64, .riscv64be => 65,
         .s390x => 65,
diff --git a/lib/std/debug/cpu_context.zig b/lib/std/debug/cpu_context.zig
index 6243131d25..b899d76f1b 100644
--- a/lib/std/debug/cpu_context.zig
+++ b/lib/std/debug/cpu_context.zig
@@ -810,7 +810,7 @@ pub const Mips = extern struct {
     pub fn dwarfRegisterBytes(ctx: *Mips, register_num: u16) DwarfRegisterError![]u8 {
         switch (register_num) {
             0...31 => return @ptrCast(&ctx.r[register_num]),
-            37 => return @ptrCast(&ctx.pc),
+            66 => return @ptrCast(&ctx.pc),
 
             else => return error.InvalidRegister,
         }