From 0183b4109a04ad78722b919366005df84878cf5d Mon Sep 17 00:00:00 2001 From: Erik Desjardins Date: Sun, 29 Nov 2020 19:49:41 -0500 Subject: [PATCH 1/2] Pass arguments up to 2*usize by value --- compiler/rustc_middle/src/ty/layout.rs | 12 ++++++------ ...n-value-in-reg.rs => arg-return-value-in-reg.rs} | 4 ++-- src/test/codegen/union-abi.rs | 13 +++++++++---- 3 files changed, 17 insertions(+), 12 deletions(-) rename src/test/codegen/{return-value-in-reg.rs => arg-return-value-in-reg.rs} (74%) diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs index 8bdc7efa0bb..ffc24aef579 100644 --- a/compiler/rustc_middle/src/ty/layout.rs +++ b/compiler/rustc_middle/src/ty/layout.rs @@ -2818,7 +2818,7 @@ fn adjust_for_abi(&mut self, cx: &C, abi: SpecAbi) { || abi == SpecAbi::RustIntrinsic || abi == SpecAbi::PlatformIntrinsic { - let fixup = |arg: &mut ArgAbi<'tcx, Ty<'tcx>>, is_ret: bool| { + let fixup = |arg: &mut ArgAbi<'tcx, Ty<'tcx>>| { if arg.is_ignore() { return; } @@ -2856,9 +2856,9 @@ fn adjust_for_abi(&mut self, cx: &C, abi: SpecAbi) { _ => return, } - // Return structures up to 2 pointers in size by value, matching `ScalarPair`. LLVM - // will usually return these in 2 registers, which is more efficient than by-ref. - let max_by_val_size = if is_ret { Pointer.size(cx) * 2 } else { Pointer.size(cx) }; + // Pass and return structures up to 2 pointers in size by value, matching `ScalarPair`. + // LLVM will usually pass these in 2 registers, which is more efficient than by-ref. + let max_by_val_size = Pointer.size(cx) * 2; let size = arg.layout.size; if arg.layout.is_unsized() || size > max_by_val_size { @@ -2870,9 +2870,9 @@ fn adjust_for_abi(&mut self, cx: &C, abi: SpecAbi) { arg.cast_to(Reg { kind: RegKind::Integer, size }); } }; - fixup(&mut self.ret, true); + fixup(&mut self.ret); for arg in &mut self.args { - fixup(arg, false); + fixup(arg); } return; } diff --git a/src/test/codegen/return-value-in-reg.rs b/src/test/codegen/arg-return-value-in-reg.rs similarity index 74% rename from src/test/codegen/return-value-in-reg.rs rename to src/test/codegen/arg-return-value-in-reg.rs index 4bc0136c5e3..a1815e37cf2 100644 --- a/src/test/codegen/return-value-in-reg.rs +++ b/src/test/codegen/arg-return-value-in-reg.rs @@ -1,4 +1,4 @@ -//! This test checks that types of up to 128 bits are returned by-value instead of via out-pointer. +//! Check that types of up to 128 bits are passed and returned by-value instead of via pointer. // compile-flags: -C no-prepopulate-passes -O // only-x86_64 @@ -11,7 +11,7 @@ pub struct S { c: u32, } -// CHECK: define i128 @modify(%S* noalias nocapture dereferenceable(16) %s) +// CHECK: define i128 @modify(i128 %0) #[no_mangle] pub fn modify(s: S) -> S { S { a: s.a + s.a, b: s.b + s.b, c: s.c + s.c } diff --git a/src/test/codegen/union-abi.rs b/src/test/codegen/union-abi.rs index afea01e9a2d..f282fd23705 100644 --- a/src/test/codegen/union-abi.rs +++ b/src/test/codegen/union-abi.rs @@ -63,11 +63,16 @@ pub union UnionU128{a:u128} #[no_mangle] pub fn test_UnionU128(_: UnionU128) -> UnionU128 { loop {} } -#[repr(C)] -pub union CUnionU128{a:u128} -// CHECK: define void @test_CUnionU128(%CUnionU128* {{.*}} %_1) +pub union UnionU128x2{a:(u128, u128)} +// CHECK: define void @test_UnionU128x2(i128 %_1.0, i128 %_1.1) #[no_mangle] -pub fn test_CUnionU128(_: CUnionU128) { loop {} } +pub fn test_UnionU128x2(_: UnionU128x2) { loop {} } + +#[repr(C)] +pub union CUnionU128x2{a:(u128, u128)} +// CHECK: define void @test_CUnionU128x2(%CUnionU128x2* {{.*}} %_1) +#[no_mangle] +pub fn test_CUnionU128x2(_: CUnionU128x2) { loop {} } pub union UnionBool { b:bool } // CHECK: define zeroext i1 @test_UnionBool(i8 %b) From 53943d6debc78efafa037744774d3216d22a10ad Mon Sep 17 00:00:00 2001 From: Erik Desjardins Date: Mon, 30 Nov 2020 01:21:47 -0500 Subject: [PATCH 2/2] make test work in llvm 9 --- src/test/codegen/arg-return-value-in-reg.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/test/codegen/arg-return-value-in-reg.rs b/src/test/codegen/arg-return-value-in-reg.rs index a1815e37cf2..a69291d4782 100644 --- a/src/test/codegen/arg-return-value-in-reg.rs +++ b/src/test/codegen/arg-return-value-in-reg.rs @@ -11,7 +11,7 @@ pub struct S { c: u32, } -// CHECK: define i128 @modify(i128 %0) +// CHECK: define i128 @modify(i128{{( %0)?}}) #[no_mangle] pub fn modify(s: S) -> S { S { a: s.a + s.a, b: s.b + s.b, c: s.c + s.c }