From 09e4035e79caea3174bb3f60ba005fe5838d82e5 Mon Sep 17 00:00:00 2001
From: David Rubin <david@vortan.dev>
Date: Thu, 6 Nov 2025 20:12:35 -0800
Subject: [PATCH 1/2] llvm: clobber `rdx` instead of `edx` for x86-64 valgrind
 request

---
 src/codegen/llvm.zig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index 6b891c1ab5a9..2711deba5cfd 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -11735,7 +11735,7 @@ pub const FuncGen = struct {
                 \\ rolq  $$61, %rdi ; rolq $$51, %rdi
                 \\ xchgq %rbx, %rbx
                 ,
-                .constraints = "={rdx},{rax},{edx},~{cc},~{memory}",
+                .constraints = "={rdx},{rax},{rdx},~{cc},~{memory}",
             },
             else => unreachable,
         };

From 483f9bd3670a52242d799dd4eee4273bdc714e8a Mon Sep 17 00:00:00 2001
From: David Rubin <david@vortan.dev>
Date: Thu, 6 Nov 2025 20:27:38 -0800
Subject: [PATCH 2/2] llvm: add extra clobbers to valgrind requests

This seems to work around a very puzzling miscompilation first
present in LLVM 21.x. We already unconditionally add these
clobbers to inline assembly that came from the source, the
valgrind requests should also contain them.
---
 src/codegen/llvm.zig | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index 2711deba5cfd..a56311b32542 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -11672,7 +11672,7 @@ pub const FuncGen = struct {
                 \\ srl $$0,  $$0,  19
                 \\ or  $$13, $$13, $$13
                 ,
-                .constraints = "={$11},{$12},{$11},~{memory}",
+                .constraints = "={$11},{$12},{$11},~{memory},~{$1}",
             },
             .mips64, .mips64el => .{
                 .template =
@@ -11680,7 +11680,7 @@ pub const FuncGen = struct {
                 \\ dsll $$0,  $$0,  29   ; dsll $$0, $$0, 19
                 \\ or   $$13, $$13, $$13
                 ,
-                .constraints = "={$11},{$12},{$11},~{memory}",
+                .constraints = "={$11},{$12},{$11},~{memory},~{$1}",
             },
             .powerpc, .powerpcle => .{
                 .template =
@@ -11727,7 +11727,7 @@ pub const FuncGen = struct {
                 \\ roll  $$61, %edi ; roll $$51, %edi
                 \\ xchgl %ebx, %ebx
                 ,
-                .constraints = "={edx},{eax},{edx},~{cc},~{memory}",
+                .constraints = "={edx},{eax},{edx},~{cc},~{memory},~{dirflag},~{fpsr},~{flags}",
             },
             .x86_64 => .{
                 .template =
@@ -11735,7 +11735,7 @@ pub const FuncGen = struct {
                 \\ rolq  $$61, %rdi ; rolq $$51, %rdi
                 \\ xchgq %rbx, %rbx
                 ,
-                .constraints = "={rdx},{rax},{rdx},~{cc},~{memory}",
+                .constraints = "={rdx},{rax},{rdx},~{cc},~{memory},~{dirflag},~{fpsr},~{flags}",
             },
             else => unreachable,
         };