llvm-6502/test/CodeGen/X86/x86-64-sret-return.ll
Dan Gohman 61a9213440 Implement an x86-64 ABI detail of passing structs by hidden first
argument. The x86-64 ABI requires the incoming value of %rdi to
be copied to %rax on exit from a function that is returning a
large C struct.

Also, add a README-X86-64 entry detailing the missed optimization
opportunity and proposing an alternative approach.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50075 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-21 23:59:07 +00:00

55 lines
3.0 KiB
LLVM

; RUN: llvm-as < %s | llc | grep {movq %rdi, %rax}
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
target triple = "x86_64-apple-darwin8"
%struct.foo = type { [4 x i64] }
define void @bar(%struct.foo* noalias sret %agg.result, %struct.foo* %d) nounwind {
entry:
%d_addr = alloca %struct.foo* ; <%struct.foo**> [#uses=2]
%memtmp = alloca %struct.foo, align 8 ; <%struct.foo*> [#uses=1]
%"alloca point" = bitcast i32 0 to i32 ; <i32> [#uses=0]
store %struct.foo* %d, %struct.foo** %d_addr
%tmp = load %struct.foo** %d_addr, align 8 ; <%struct.foo*> [#uses=1]
%tmp1 = getelementptr %struct.foo* %agg.result, i32 0, i32 0 ; <[4 x i64]*> [#uses=4]
%tmp2 = getelementptr %struct.foo* %tmp, i32 0, i32 0 ; <[4 x i64]*> [#uses=4]
%tmp3 = getelementptr [4 x i64]* %tmp1, i32 0, i32 0 ; <i64*> [#uses=1]
%tmp4 = getelementptr [4 x i64]* %tmp2, i32 0, i32 0 ; <i64*> [#uses=1]
%tmp5 = load i64* %tmp4, align 8 ; <i64> [#uses=1]
store i64 %tmp5, i64* %tmp3, align 8
%tmp6 = getelementptr [4 x i64]* %tmp1, i32 0, i32 1 ; <i64*> [#uses=1]
%tmp7 = getelementptr [4 x i64]* %tmp2, i32 0, i32 1 ; <i64*> [#uses=1]
%tmp8 = load i64* %tmp7, align 8 ; <i64> [#uses=1]
store i64 %tmp8, i64* %tmp6, align 8
%tmp9 = getelementptr [4 x i64]* %tmp1, i32 0, i32 2 ; <i64*> [#uses=1]
%tmp10 = getelementptr [4 x i64]* %tmp2, i32 0, i32 2 ; <i64*> [#uses=1]
%tmp11 = load i64* %tmp10, align 8 ; <i64> [#uses=1]
store i64 %tmp11, i64* %tmp9, align 8
%tmp12 = getelementptr [4 x i64]* %tmp1, i32 0, i32 3 ; <i64*> [#uses=1]
%tmp13 = getelementptr [4 x i64]* %tmp2, i32 0, i32 3 ; <i64*> [#uses=1]
%tmp14 = load i64* %tmp13, align 8 ; <i64> [#uses=1]
store i64 %tmp14, i64* %tmp12, align 8
%tmp15 = getelementptr %struct.foo* %memtmp, i32 0, i32 0 ; <[4 x i64]*> [#uses=4]
%tmp16 = getelementptr %struct.foo* %agg.result, i32 0, i32 0 ; <[4 x i64]*> [#uses=4]
%tmp17 = getelementptr [4 x i64]* %tmp15, i32 0, i32 0 ; <i64*> [#uses=1]
%tmp18 = getelementptr [4 x i64]* %tmp16, i32 0, i32 0 ; <i64*> [#uses=1]
%tmp19 = load i64* %tmp18, align 8 ; <i64> [#uses=1]
store i64 %tmp19, i64* %tmp17, align 8
%tmp20 = getelementptr [4 x i64]* %tmp15, i32 0, i32 1 ; <i64*> [#uses=1]
%tmp21 = getelementptr [4 x i64]* %tmp16, i32 0, i32 1 ; <i64*> [#uses=1]
%tmp22 = load i64* %tmp21, align 8 ; <i64> [#uses=1]
store i64 %tmp22, i64* %tmp20, align 8
%tmp23 = getelementptr [4 x i64]* %tmp15, i32 0, i32 2 ; <i64*> [#uses=1]
%tmp24 = getelementptr [4 x i64]* %tmp16, i32 0, i32 2 ; <i64*> [#uses=1]
%tmp25 = load i64* %tmp24, align 8 ; <i64> [#uses=1]
store i64 %tmp25, i64* %tmp23, align 8
%tmp26 = getelementptr [4 x i64]* %tmp15, i32 0, i32 3 ; <i64*> [#uses=1]
%tmp27 = getelementptr [4 x i64]* %tmp16, i32 0, i32 3 ; <i64*> [#uses=1]
%tmp28 = load i64* %tmp27, align 8 ; <i64> [#uses=1]
store i64 %tmp28, i64* %tmp26, align 8
br label %return
return: ; preds = %entry
ret void
}