Commit a1827d5977

Jacob Young <jacobly0@users.noreply.github.com>
2025-11-26 08:34:43
x86_64: fix abi of a struct that partially fits in registers
Closes #26035
master
1 parent 51bb2b3
Changed files (3)
src
codegen
x86_64
CodeGen.zig
test
c_abi
cfuncs.c
main.zig
src/codegen/x86_64/CodeGen.zig
@@ -181159,6 +181159,9 @@ fn resolveCallingConventionValues(
                     else => unreachable,
                 }
 
+                const save_param_gpr_index = param_gpr_index;
+                const save_param_sse_index = param_gpr_index;
+
                 var arg_mcv: [4]MCValue = undefined;
                 var arg_mcv_len: u32 = 0;
 
@@ -181258,6 +181261,9 @@ fn resolveCallingConventionValues(
                     continue;
                 }
 
+                param_gpr_index = save_param_gpr_index;
+                param_sse_index = save_param_sse_index;
+
                 const param_align = ty.abiAlignment(zcu).max(.@"8");
                 result.stack_byte_count = @intCast(param_align.forward(result.stack_byte_count));
                 result.stack_align = result.stack_align.max(param_align);
test/c_abi/cfuncs.c
@@ -212,55 +212,64 @@ struct Struct_u64_u64 {
 
 struct Struct_u64_u64 zig_ret_struct_u64_u64(void);
 
-void zig_struct_u64_u64_0(struct Struct_u64_u64);
-void zig_struct_u64_u64_1(size_t, struct Struct_u64_u64);
-void zig_struct_u64_u64_2(size_t, size_t, struct Struct_u64_u64);
-void zig_struct_u64_u64_3(size_t, size_t, size_t, struct Struct_u64_u64);
-void zig_struct_u64_u64_4(size_t, size_t, size_t, size_t, struct Struct_u64_u64);
-void zig_struct_u64_u64_5(size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64);
-void zig_struct_u64_u64_6(size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64);
-void zig_struct_u64_u64_7(size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64);
-void zig_struct_u64_u64_8(size_t, size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64);
+void zig_struct_u64_u64_0(struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_1(size_t, struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_2(size_t, size_t, struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_3(size_t, size_t, size_t, struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_4(size_t, size_t, size_t, size_t, struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_5(size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_6(size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_7(size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64, size_t);
+void zig_struct_u64_u64_8(size_t, size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64, size_t);
 
 struct Struct_u64_u64 c_ret_struct_u64_u64(void) {
     return (struct Struct_u64_u64){ 21, 22 };
 }
 
-void c_struct_u64_u64_0(struct Struct_u64_u64 s) {
+void c_struct_u64_u64_0(struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 23);
     assert_or_panic(s.b == 24);
+    assert_or_panic(i == 1);
 }
-void c_struct_u64_u64_1(size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_1(size_t a0, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 25);
     assert_or_panic(s.b == 26);
+    assert_or_panic(i == 2);
 }
-void c_struct_u64_u64_2(size_t, size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_2(size_t, size_t, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 27);
     assert_or_panic(s.b == 28);
+    assert_or_panic(i == 3);
 }
-void c_struct_u64_u64_3(size_t, size_t, size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_3(size_t, size_t, size_t, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 29);
     assert_or_panic(s.b == 30);
+    assert_or_panic(i == 4);
 }
-void c_struct_u64_u64_4(size_t, size_t, size_t, size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_4(size_t, size_t, size_t, size_t, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 31);
     assert_or_panic(s.b == 32);
+    assert_or_panic(i == 5);
 }
-void c_struct_u64_u64_5(size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_5(size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 33);
     assert_or_panic(s.b == 34);
+    assert_or_panic(i == 6);
 }
-void c_struct_u64_u64_6(size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_6(size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 35);
     assert_or_panic(s.b == 36);
+    assert_or_panic(i == 7);
 }
-void c_struct_u64_u64_7(size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_7(size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 37);
     assert_or_panic(s.b == 38);
+    assert_or_panic(i == 8);
 }
-void c_struct_u64_u64_8(size_t, size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s) {
+void c_struct_u64_u64_8(size_t, size_t, size_t, size_t, size_t, size_t, size_t, size_t, struct Struct_u64_u64 s, size_t i) {
     assert_or_panic(s.a == 39);
     assert_or_panic(s.b == 40);
+    assert_or_panic(i == 9);
 }
 
 struct Struct_f32 {
@@ -2737,15 +2746,15 @@ void run_c_tests(void) {
         struct Struct_u64_u64 s = zig_ret_struct_u64_u64();
         assert_or_panic(s.a == 1);
         assert_or_panic(s.b == 2);
-        zig_struct_u64_u64_0((struct Struct_u64_u64){ .a = 3, .b = 4 });
-        zig_struct_u64_u64_1(0, (struct Struct_u64_u64){ .a = 5, .b = 6 });
-        zig_struct_u64_u64_2(0, 1, (struct Struct_u64_u64){ .a = 7, .b = 8 });
-        zig_struct_u64_u64_3(0, 1, 2, (struct Struct_u64_u64){ .a = 9, .b = 10 });
-        zig_struct_u64_u64_4(0, 1, 2, 3, (struct Struct_u64_u64){ .a = 11, .b = 12 });
-        zig_struct_u64_u64_5(0, 1, 2, 3, 4, (struct Struct_u64_u64){ .a = 13, .b = 14 });
-        zig_struct_u64_u64_6(0, 1, 2, 3, 4, 5, (struct Struct_u64_u64){ .a = 15, .b = 16 });
-        zig_struct_u64_u64_7(0, 1, 2, 3, 4, 5, 6, (struct Struct_u64_u64){ .a = 17, .b = 18 });
-        zig_struct_u64_u64_8(0, 1, 2, 3, 4, 5, 6, 7, (struct Struct_u64_u64){ .a = 19, .b = 20 });
+        zig_struct_u64_u64_0((struct Struct_u64_u64){ .a = 3, .b = 4 }, 1);
+        zig_struct_u64_u64_1(0, (struct Struct_u64_u64){ .a = 5, .b = 6 }, 2);
+        zig_struct_u64_u64_2(0, 1, (struct Struct_u64_u64){ .a = 7, .b = 8 }, 3);
+        zig_struct_u64_u64_3(0, 1, 2, (struct Struct_u64_u64){ .a = 9, .b = 10 }, 4);
+        zig_struct_u64_u64_4(0, 1, 2, 3, (struct Struct_u64_u64){ .a = 11, .b = 12 }, 5);
+        zig_struct_u64_u64_5(0, 1, 2, 3, 4, (struct Struct_u64_u64){ .a = 13, .b = 14 }, 6);
+        zig_struct_u64_u64_6(0, 1, 2, 3, 4, 5, (struct Struct_u64_u64){ .a = 15, .b = 16 }, 7);
+        zig_struct_u64_u64_7(0, 1, 2, 3, 4, 5, 6, (struct Struct_u64_u64){ .a = 17, .b = 18 }, 8);
+        zig_struct_u64_u64_8(0, 1, 2, 3, 4, 5, 6, 7, (struct Struct_u64_u64){ .a = 19, .b = 20 }, 9);
     }
 
 #if !defined(ZIG_RISCV64)
test/c_abi/main.zig
@@ -278,54 +278,63 @@ export fn zig_ret_struct_u64_u64() Struct_u64_u64 {
     return .{ .a = 1, .b = 2 };
 }
 
-export fn zig_struct_u64_u64_0(s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_0(s: Struct_u64_u64, i: usize) void {
     expect(s.a == 3) catch @panic("test failure");
     expect(s.b == 4) catch @panic("test failure");
+    expect(i == 1) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_1(_: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_1(_: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 5) catch @panic("test failure");
     expect(s.b == 6) catch @panic("test failure");
+    expect(i == 2) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_2(_: usize, _: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_2(_: usize, _: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 7) catch @panic("test failure");
     expect(s.b == 8) catch @panic("test failure");
+    expect(i == 3) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_3(_: usize, _: usize, _: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_3(_: usize, _: usize, _: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 9) catch @panic("test failure");
     expect(s.b == 10) catch @panic("test failure");
+    expect(i == 4) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_4(_: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_4(_: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 11) catch @panic("test failure");
     expect(s.b == 12) catch @panic("test failure");
+    expect(i == 5) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_5(_: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_5(_: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 13) catch @panic("test failure");
     expect(s.b == 14) catch @panic("test failure");
+    expect(i == 6) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_6(_: usize, _: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_6(_: usize, _: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 15) catch @panic("test failure");
     expect(s.b == 16) catch @panic("test failure");
+    expect(i == 7) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_7(_: usize, _: usize, _: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_7(_: usize, _: usize, _: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 17) catch @panic("test failure");
     expect(s.b == 18) catch @panic("test failure");
+    expect(i == 8) catch @panic("test failure");
 }
-export fn zig_struct_u64_u64_8(_: usize, _: usize, _: usize, _: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64) void {
+export fn zig_struct_u64_u64_8(_: usize, _: usize, _: usize, _: usize, _: usize, _: usize, _: usize, _: usize, s: Struct_u64_u64, i: usize) void {
     expect(s.a == 19) catch @panic("test failure");
     expect(s.b == 20) catch @panic("test failure");
+    expect(i == 9) catch @panic("test failure");
 }
 
 extern fn c_ret_struct_u64_u64() Struct_u64_u64;
 
-extern fn c_struct_u64_u64_0(Struct_u64_u64) void;
-extern fn c_struct_u64_u64_1(usize, Struct_u64_u64) void;
-extern fn c_struct_u64_u64_2(usize, usize, Struct_u64_u64) void;
-extern fn c_struct_u64_u64_3(usize, usize, usize, Struct_u64_u64) void;
-extern fn c_struct_u64_u64_4(usize, usize, usize, usize, Struct_u64_u64) void;
-extern fn c_struct_u64_u64_5(usize, usize, usize, usize, usize, Struct_u64_u64) void;
-extern fn c_struct_u64_u64_6(usize, usize, usize, usize, usize, usize, Struct_u64_u64) void;
-extern fn c_struct_u64_u64_7(usize, usize, usize, usize, usize, usize, usize, Struct_u64_u64) void;
-extern fn c_struct_u64_u64_8(usize, usize, usize, usize, usize, usize, usize, usize, Struct_u64_u64) void;
+extern fn c_struct_u64_u64_0(Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_1(usize, Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_2(usize, usize, Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_3(usize, usize, usize, Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_4(usize, usize, usize, usize, Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_5(usize, usize, usize, usize, usize, Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_6(usize, usize, usize, usize, usize, usize, Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_7(usize, usize, usize, usize, usize, usize, usize, Struct_u64_u64, usize) void;
+extern fn c_struct_u64_u64_8(usize, usize, usize, usize, usize, usize, usize, usize, Struct_u64_u64, usize) void;
 
 test "C ABI struct u64 u64" {
     if (builtin.cpu.arch.isMIPS64()) return error.SkipZigTest;
@@ -336,15 +345,15 @@ test "C ABI struct u64 u64" {
     const s = c_ret_struct_u64_u64();
     try expect(s.a == 21);
     try expect(s.b == 22);
-    c_struct_u64_u64_0(.{ .a = 23, .b = 24 });
-    c_struct_u64_u64_1(0, .{ .a = 25, .b = 26 });
-    c_struct_u64_u64_2(0, 1, .{ .a = 27, .b = 28 });
-    c_struct_u64_u64_3(0, 1, 2, .{ .a = 29, .b = 30 });
-    c_struct_u64_u64_4(0, 1, 2, 3, .{ .a = 31, .b = 32 });
-    c_struct_u64_u64_5(0, 1, 2, 3, 4, .{ .a = 33, .b = 34 });
-    c_struct_u64_u64_6(0, 1, 2, 3, 4, 5, .{ .a = 35, .b = 36 });
-    c_struct_u64_u64_7(0, 1, 2, 3, 4, 5, 6, .{ .a = 37, .b = 38 });
-    c_struct_u64_u64_8(0, 1, 2, 3, 4, 5, 6, 7, .{ .a = 39, .b = 40 });
+    c_struct_u64_u64_0(.{ .a = 23, .b = 24 }, 1);
+    c_struct_u64_u64_1(0, .{ .a = 25, .b = 26 }, 2);
+    c_struct_u64_u64_2(0, 1, .{ .a = 27, .b = 28 }, 3);
+    c_struct_u64_u64_3(0, 1, 2, .{ .a = 29, .b = 30 }, 4);
+    c_struct_u64_u64_4(0, 1, 2, 3, .{ .a = 31, .b = 32 }, 5);
+    c_struct_u64_u64_5(0, 1, 2, 3, 4, .{ .a = 33, .b = 34 }, 6);
+    c_struct_u64_u64_6(0, 1, 2, 3, 4, 5, .{ .a = 35, .b = 36 }, 7);
+    c_struct_u64_u64_7(0, 1, 2, 3, 4, 5, 6, .{ .a = 37, .b = 38 }, 8);
+    c_struct_u64_u64_8(0, 1, 2, 3, 4, 5, 6, 7, .{ .a = 39, .b = 40 }, 9);
 }
 
 const Struct_f32 = extern struct {