rust/tests/codegen/function-arguments-noopt.rs

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// compile-flags: -C opt-level=0 -C no-prepopulate-passes
// This test checks that arguments/returns in opt-level=0 builds,
// while lacking attributes used for optimization, still have ABI-affecting attributes.
#![crate_type = "lib"]
#![feature(rustc_attrs)]
pub struct S {
_field: [i32; 8],
}
// CHECK: zeroext i1 @boolean(i1 zeroext %x)
#[no_mangle]
pub fn boolean(x: bool) -> bool {
x
}
// CHECK-LABEL: @boolean_call
#[no_mangle]
pub fn boolean_call(x: bool, f: fn(bool) -> bool) -> bool {
// CHECK: call zeroext i1 %f(i1 zeroext %x)
f(x)
}
// CHECK: align 4 {{i32\*|ptr}} @borrow({{i32\*|ptr}} align 4 %x)
#[no_mangle]
pub fn borrow(x: &i32) -> &i32 {
x
}
// CHECK: align 4 {{i32\*|ptr}} @borrow_mut({{i32\*|ptr}} align 4 %x)
#[no_mangle]
pub fn borrow_mut(x: &mut i32) -> &mut i32 {
x
}
// CHECK-LABEL: @borrow_call
#[no_mangle]
pub fn borrow_call(x: &i32, f: fn(&i32) -> &i32) -> &i32 {
// CHECK: call align 4 {{i32\*|ptr}} %f({{i32\*|ptr}} align 4 %x)
f(x)
}
rustc_target: Add alignment to indirectly-passed by-value types, correcting the alignment of `byval` on x86 in the process. Commit 88e4d2c2918428d55e34cd57c11279ea839c8822 from five years ago removed support for alignment on indirectly-passed arguments because of problems with the `i686-pc-windows-msvc` target. Unfortunately, the `memcpy` optimizations I recently added to LLVM 16 depend on this to forward `memcpy`s. This commit attempts to fix the problems with `byval` parameters on that target and now correctly adds the `align` attribute. The problem is summarized in [this comment] by @eddyb. Briefly, 32-bit x86 has special alignment rules for `byval` parameters: for the most part, their alignment is forced to 4. This is not well-documented anywhere but in the Clang source. I looked at the logic in Clang `TargetInfo.cpp` and tried to replicate it here. The relevant methods in that file are `X86_32ABIInfo::getIndirectResult()` and `X86_32ABIInfo::getTypeStackAlignInBytes()`. The `align` parameter attribute for `byval` parameters in LLVM must match the platform ABI, or miscompilations will occur. Note that this doesn't use the approach suggested by eddyb, because I felt it was overkill to store the alignment in `on_stack` when special handling is really only needed for 32-bit x86. As a side effect, this should fix #80127, because it will make the `align` parameter attribute for `byval` parameters match the platform ABI on LLVM x86-64. [this comment]: https://github.com/rust-lang/rust/pull/80822#issuecomment-829985417
2022-10-31 22:38:40 -05:00
// CHECK: void @struct_({{%S\*|ptr}} sret(%S) align 4{{( %_0)?}}, {{%S\*|ptr}} align 4 %x)
#[no_mangle]
pub fn struct_(x: S) -> S {
x
}
// CHECK-LABEL: @struct_call
#[no_mangle]
pub fn struct_call(x: S, f: fn(S) -> S) -> S {
rustc_target: Add alignment to indirectly-passed by-value types, correcting the alignment of `byval` on x86 in the process. Commit 88e4d2c2918428d55e34cd57c11279ea839c8822 from five years ago removed support for alignment on indirectly-passed arguments because of problems with the `i686-pc-windows-msvc` target. Unfortunately, the `memcpy` optimizations I recently added to LLVM 16 depend on this to forward `memcpy`s. This commit attempts to fix the problems with `byval` parameters on that target and now correctly adds the `align` attribute. The problem is summarized in [this comment] by @eddyb. Briefly, 32-bit x86 has special alignment rules for `byval` parameters: for the most part, their alignment is forced to 4. This is not well-documented anywhere but in the Clang source. I looked at the logic in Clang `TargetInfo.cpp` and tried to replicate it here. The relevant methods in that file are `X86_32ABIInfo::getIndirectResult()` and `X86_32ABIInfo::getTypeStackAlignInBytes()`. The `align` parameter attribute for `byval` parameters in LLVM must match the platform ABI, or miscompilations will occur. Note that this doesn't use the approach suggested by eddyb, because I felt it was overkill to store the alignment in `on_stack` when special handling is really only needed for 32-bit x86. As a side effect, this should fix #80127, because it will make the `align` parameter attribute for `byval` parameters match the platform ABI on LLVM x86-64. [this comment]: https://github.com/rust-lang/rust/pull/80822#issuecomment-829985417
2022-10-31 22:38:40 -05:00
// CHECK: call void %f({{%S\*|ptr}} sret(%S) align 4{{( %_0)?}}, {{%S\*|ptr}} align 4 %{{.+}})
f(x)
}
// CHECK: { i8, i8 } @enum_(i1 zeroext %x.0, i8 %x.1)
#[no_mangle]
pub fn enum_(x: Option<u8>) -> Option<u8> {
x
}
// CHECK-LABEL: @enum_call
#[no_mangle]
pub fn enum_call(x: Option<u8>, f: fn(Option<u8>) -> Option<u8>) -> Option<u8> {
// CHECK: call { i8, i8 } %f(i1 zeroext %x.0, i8 %x.1)
f(x)
}