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target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
; RUN: opt < %s -instcombine -S | FileCheck %s
; END.
declare void @use(...)
@int = global i32 zeroinitializer
; Zero byte allocas should be merged if they can't be deleted.
; CHECK: @test
; CHECK: alloca
; CHECK-NOT: alloca
define void @test() {
%X = alloca [0 x i32] ; <[0 x i32]*> [#uses=1]
call void (...)* @use( [0 x i32]* %X )
%Y = alloca i32, i32 0 ; <i32*> [#uses=1]
call void (...)* @use( i32* %Y )
%Z = alloca { } ; <{ }*> [#uses=1]
call void (...)* @use( { }* %Z )
%size = load i32* @int
%A = alloca {{}}, i32 %size
call void (...)* @use( {{}}* %A )
ret void
}
; Zero byte allocas should be deleted.
; CHECK: @test2
; CHECK-NOT: alloca
define void @test2() {
%A = alloca i32 ; <i32*> [#uses=1]
store i32 123, i32* %A
ret void
}
; Zero byte allocas should be deleted.
; CHECK: @test3
; CHECK-NOT: alloca
define void @test3() {
%A = alloca { i32 } ; <{ i32 }*> [#uses=1]
%B = getelementptr { i32 }* %A, i32 0, i32 0 ; <i32*> [#uses=1]
store i32 123, i32* %B
ret void
}
; CHECK: @test4
; CHECK: = zext i32 %n to i64
; CHECK: %A = alloca i32, i64 %
define i32* @test4(i32 %n) {
%A = alloca i32, i32 %n
ret i32* %A
}
; Allocas which are only used by GEPs, bitcasts, and stores (transitively)
; should be deleted.
define void @test5() {
; CHECK: @test5
; CHECK-NOT: alloca
; CHECK-NOT: store
; CHECK: ret
entry:
%a = alloca { i32 }
%b = alloca i32*
%a.1 = getelementptr { i32 }* %a, i32 0, i32 0
store i32 123, i32* %a.1
store i32* %a.1, i32** %b
%b.1 = bitcast i32** %b to i32*
store i32 123, i32* %b.1
%a.2 = getelementptr { i32 }* %a, i32 0, i32 0
store atomic i32 2, i32* %a.2 unordered, align 4
%a.3 = getelementptr { i32 }* %a, i32 0, i32 0
store atomic i32 3, i32* %a.3 release, align 4
%a.4 = getelementptr { i32 }* %a, i32 0, i32 0
store atomic i32 4, i32* %a.4 seq_cst, align 4
ret void
}
declare void @f(i32* %p)
; Check that we don't delete allocas in some erroneous cases.
define void @test6() {
; CHECK: @test6
; CHECK-NOT: ret
; CHECK: alloca
; CHECK-NEXT: alloca
; CHECK: ret
entry:
%a = alloca { i32 }
%b = alloca i32
%a.1 = getelementptr { i32 }* %a, i32 0, i32 0
store volatile i32 123, i32* %a.1
tail call void @f(i32* %b)
ret void
}
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