llvm-6502/test/Transforms/DeadArgElim/multdeadretval.ll
Matthijs Kooijman eb32b453b3 Make deadargelim a bit less smart, so it doesn't choke on nested structs as
return values that are still (partially) live. Instead of updating all uses of
a call instruction after removing some elements, it now just rebuilds the
original struct (With undef gaps where the unused values were) and leaves it to
instcombine to clean this up.

The added testcase still fails currently, but this is due to instcombine which
isn't good enough yet. I will fix that part next.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53608 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-15 14:03:10 +00:00

69 lines
2.6 KiB
LLVM

; This test sees if return values (and arguments) are properly removed when they
; are unused. All unused values are typed i16, so we can easily check. We also
; run instcombine to fold insert/extractvalue chains and we run dce to clean up
; any remaining dead stuff.
; RUN: llvm-as < %s | opt -deadargelim -instcombine -dce | llvm-dis | not grep i16
define internal {i16, i32} @test(i16 %DEADARG) {
%A = insertvalue {i16,i32} undef, i16 1, 0
%B = insertvalue {i16,i32} %A, i32 1001, 1
ret {i16,i32} %B
}
define internal {i32, i16} @test2() {
%DEAD = call i16 @test4()
%A = insertvalue {i32,i16} undef, i32 1, 0
%B = insertvalue {i32,i16} %A, i16 %DEAD, 1
ret {i32,i16} %B
}
; Dead argument, used to check if the second result of test2 is dead even when
; it's used as a dead argument
define internal i32 @test3(i16 %A) {
%ret = call {i16, i32} @test( i16 %A ) ; <i32> [#uses=0]
%DEAD = extractvalue {i16, i32} %ret, 0
%LIVE = extractvalue {i16, i32} %ret, 1
ret i32 %LIVE
}
define internal i16 @test4() {
ret i16 0
}
; Multiple return values, multiple live return values
define internal {i32, i32, i16} @test5() {
%A = insertvalue {i32,i32,i16} undef, i32 1, 0
%B = insertvalue {i32,i32,i16} %A, i32 2, 1
%C = insertvalue {i32,i32,i16} %B, i16 3, 2
ret {i32, i32, i16} %C
}
; Nested return values
define internal {{i32}, {i16, i16}} @test6() {
%A = insertvalue {{i32}, {i16, i16}} undef, i32 1, 0, 0
%B = insertvalue {{i32}, {i16, i16}} %A, i16 2, 1, 0
%C = insertvalue {{i32}, {i16, i16}} %B, i16 3, 1, 1
ret {{i32}, {i16, i16}} %C
}
define i32 @main() {
%ret = call {i32, i16} @test2() ; <i32> [#uses=1]
%LIVE = extractvalue {i32, i16} %ret, 0
%DEAD = extractvalue {i32, i16} %ret, 1
%Y = add i32 %LIVE, -123 ; <i32> [#uses=1]
%LIVE2 = call i32 @test3(i16 %DEAD) ; <i32> [#uses=1]
%Z = add i32 %LIVE2, %Y ; <i32> [#uses=1]
%ret1 = call { i32, i32, i16 } @test5 ()
%LIVE3 = extractvalue { i32, i32, i16} %ret1, 0
%LIVE4 = extractvalue { i32, i32, i16} %ret1, 1
%DEAD2 = extractvalue { i32, i32, i16} %ret1, 2
%V = add i32 %LIVE3, %LIVE4
%W = add i32 %Z, %V
%ret2 = call { { i32 }, { i16, i16 } } @test6 ()
%LIVE5 = extractvalue { { i32 }, { i16, i16 } } %ret2, 0, 0
%DEAD3 = extractvalue { { i32 }, { i16, i16 } } %ret2, 1, 0
%DEAD4 = extractvalue { { i32 }, { i16, i16 } } %ret2, 1, 1
%Q = add i32 %W, %LIVE5
ret i32 %Q
}