Rollup merge of #137094 - RalfJung:softfloat-means-no-simd, r=tgross35

x86_win64 ABI: do not use xmm0 with softfloat ABI

This adjusts https://github.com/rust-lang/rust/pull/134290 to not apply the new logic to targets marked as "softfloat". That fixes most instances of the issue brought up [here](https://github.com/rust-lang/rust/issues/116558#issuecomment-2661027437).

r? `@tgross35`

1 files changed, 23 insertions, 15 deletions

diff --git a/tests/codegen/i128-x86-callconv.rs b/tests/codegen/i128-x86-callconv.rs
index 9a9c9002fc0..41c30c09c1a 100644
--- a/tests/codegen/i128-x86-callconv.rs
+++ b/tests/codegen/i128-x86-callconv.rs
@@ -4,13 +4,18 @@
 //@ compile-flags: -Copt-level=1
 
 //@ add-core-stubs
-//@ revisions: MSVC MINGW
+//@ revisions: MSVC MINGW softfloat
 //@ [MSVC] needs-llvm-components: x86
-//@ [MINGW] needs-llvm-components: x86
 //@ [MSVC] compile-flags: --target x86_64-pc-windows-msvc
-//@ [MINGW] compile-flags: --target x86_64-pc-windows-gnu
+// Use `WIN` as a common prefix for MSVC and MINGW but *not* the softfloat test.
 //@ [MSVC] filecheck-flags: --check-prefix=WIN
+//@ [MINGW] needs-llvm-components: x86
+//@ [MINGW] compile-flags: --target x86_64-pc-windows-gnu
 //@ [MINGW] filecheck-flags: --check-prefix=WIN
+// The `x86_64-unknown-uefi` target also uses the Windows calling convention,
+// but does not have SSE registers available.
+//@ [softfloat] needs-llvm-components: x86
+//@ [softfloat] compile-flags: --target x86_64-unknown-uefi
 
 #![crate_type = "lib"]
 #![no_std]
@@ -28,24 +33,26 @@ extern "C" {
 pub extern "C" fn pass(_arg0: u32, arg1: i128) {
     // CHECK-LABEL: @pass(
     // i128 is passed indirectly on Windows. It should load the pointer to the stack and pass
-    // a pointer to that allocation.
-    // WIN-SAME: %_arg0, ptr{{.*}} %arg1)
-    // WIN: [[PASS:%[_0-9]+]] = alloca [16 x i8], align 16
-    // WIN: [[LOADED:%[_0-9]+]] = load i128, ptr %arg1
-    // WIN: store i128 [[LOADED]], ptr [[PASS]]
-    // WIN: call void @extern_call
+    // a pointer to that allocation. The softfloat ABI works the same.
+    // CHECK-SAME: %_arg0, ptr{{.*}} %arg1)
+    // CHECK: [[PASS:%[_0-9]+]] = alloca [16 x i8], align 16
+    // CHECK: [[LOADED:%[_0-9]+]] = load i128, ptr %arg1
+    // CHECK: store i128 [[LOADED]], ptr [[PASS]]
+    // CHECK: call void @extern_call
     unsafe { extern_call(arg1) };
 }
 
 // Check that we produce the correct return ABI
 #[no_mangle]
 pub extern "C" fn ret(_arg0: u32, arg1: i128) -> i128 {
-    // CHECK-LABEL: @ret(
+    // WIN-LABEL: @ret(
     // i128 is returned in xmm0 on Windows
     // FIXME(#134288): This may change for the `-msvc` targets in the future.
     // WIN-SAME: i32{{.*}} %_arg0, ptr{{.*}} %arg1)
     // WIN: [[LOADED:%[_0-9]+]] = load <16 x i8>, ptr %arg1
     // WIN-NEXT: ret <16 x i8> [[LOADED]]
+    // The softfloat ABI returns this indirectly.
+    // softfloat-LABEL: i128 @ret(i32{{.*}} %_arg0, ptr{{.*}} %arg1)
     arg1
 }
 
@@ -57,6 +64,7 @@ pub extern "C" fn forward(dst: *mut i128) {
     // WIN: [[RETURNED:%[_0-9]+]] = tail call <16 x i8> @extern_ret()
     // WIN: store <16 x i8> [[RETURNED]], ptr %dst
     // WIN: ret void
+    // softfloat: [[RETURNED:%[_0-9]+]] = tail call {{.*}}i128 @extern_ret()
     unsafe { *dst = extern_ret() };
 }
 
@@ -70,10 +78,10 @@ struct RetAggregate {
 pub extern "C" fn ret_aggregate(_arg0: u32, arg1: i128) -> RetAggregate {
     // CHECK-LABEL: @ret_aggregate(
     // Aggregates should also be returned indirectly
-    // WIN-SAME: ptr{{.*}}sret([32 x i8]){{.*}}[[RET:%[_0-9]+]], i32{{.*}}%_arg0, ptr{{.*}}%arg1)
-    // WIN: [[LOADED:%[_0-9]+]] = load i128, ptr %arg1
-    // WIN: [[GEP:%[_0-9]+]] = getelementptr{{.*}}, ptr [[RET]]
-    // WIN: store i128 [[LOADED]], ptr [[GEP]]
-    // WIN: ret void
+    // CHECK-SAME: ptr{{.*}}sret([32 x i8]){{.*}}[[RET:%[_0-9]+]], i32{{.*}}%_arg0, ptr{{.*}}%arg1)
+    // CHECK: [[LOADED:%[_0-9]+]] = load i128, ptr %arg1
+    // CHECK: [[GEP:%[_0-9]+]] = getelementptr{{.*}}, ptr [[RET]]
+    // CHECK: store i128 [[LOADED]], ptr [[GEP]]
+    // CHECK: ret void
     RetAggregate { a: 1, b: arg1 }
 }