llvm-6502/test/Transforms/DeadStoreElimination/simple.ll
Nick Lewycky 4a3935c27e A dead malloc, a free(NULL) and a free(undef) are all trivially dead
instructions.

This doesn't introduce any optimizations we weren't doing before (except
potentially due to pass ordering issues), now passes will eliminate them sooner
as part of their own cleanups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142787 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-24 04:35:36 +00:00

261 lines
6.9 KiB
LLVM

; RUN: opt < %s -basicaa -dse -S | FileCheck %s
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"
declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
declare i8* @llvm.init.trampoline(i8*, i8*, i8*)
define void @test1(i32* %Q, i32* %P) {
%DEAD = load i32* %Q
store i32 %DEAD, i32* %P
store i32 0, i32* %P
ret void
; CHECK: @test1
; CHECK-NEXT: store i32 0, i32* %P
; CHECK-NEXT: ret void
}
; PR8576 - Should delete store of 10 even though p/q are may aliases.
define void @test2(i32 *%p, i32 *%q) {
store i32 10, i32* %p, align 4
store i32 20, i32* %q, align 4
store i32 30, i32* %p, align 4
ret void
; CHECK: @test2
; CHECK-NEXT: store i32 20
}
; PR8677
@g = global i32 1
define i32 @test3(i32* %g_addr) nounwind {
; CHECK: @test3
; CHECK: load i32* %g_addr
%g_value = load i32* %g_addr, align 4
store i32 -1, i32* @g, align 4
store i32 %g_value, i32* %g_addr, align 4
%tmp3 = load i32* @g, align 4
ret i32 %tmp3
}
define void @test4(i32* %Q) {
%a = load i32* %Q
store volatile i32 %a, i32* %Q
ret void
; CHECK: @test4
; CHECK-NEXT: load i32
; CHECK-NEXT: store volatile
; CHECK-NEXT: ret void
}
define void @test5(i32* %Q) {
%a = load volatile i32* %Q
store i32 %a, i32* %Q
ret void
; CHECK: @test5
; CHECK-NEXT: load volatile
; CHECK-NEXT: ret void
}
; Should delete store of 10 even though memset is a may-store to P (P and Q may
; alias).
define void @test6(i32 *%p, i8 *%q) {
store i32 10, i32* %p, align 4 ;; dead.
call void @llvm.memset.p0i8.i64(i8* %q, i8 42, i64 900, i32 1, i1 false)
store i32 30, i32* %p, align 4
ret void
; CHECK: @test6
; CHECK-NEXT: call void @llvm.memset
}
; Should delete store of 10 even though memcpy is a may-store to P (P and Q may
; alias).
define void @test7(i32 *%p, i8 *%q, i8* noalias %r) {
store i32 10, i32* %p, align 4 ;; dead.
call void @llvm.memcpy.p0i8.p0i8.i64(i8* %q, i8* %r, i64 900, i32 1, i1 false)
store i32 30, i32* %p, align 4
ret void
; CHECK: @test7
; CHECK-NEXT: call void @llvm.memcpy
}
; Do not delete stores that are only partially killed.
define i32 @test8() {
%V = alloca i32
store i32 1234567, i32* %V
%V2 = bitcast i32* %V to i8*
store i8 0, i8* %V2
%X = load i32* %V
ret i32 %X
; CHECK: @test8
; CHECK: store i32 1234567
}
; Test for byval handling.
%struct.x = type { i32, i32, i32, i32 }
define void @test9(%struct.x* byval %a) nounwind {
%tmp2 = getelementptr %struct.x* %a, i32 0, i32 0
store i32 1, i32* %tmp2, align 4
ret void
; CHECK: @test9
; CHECK-NEXT: ret void
}
; va_arg has fuzzy dependence, the store shouldn't be zapped.
define double @test10(i8* %X) {
%X_addr = alloca i8*
store i8* %X, i8** %X_addr
%tmp.0 = va_arg i8** %X_addr, double
ret double %tmp.0
; CHECK: @test10
; CHECK: store
}
; DSE should delete the dead trampoline.
declare void @test11f()
define void @test11() {
; CHECK: @test11
%storage = alloca [10 x i8], align 16 ; <[10 x i8]*> [#uses=1]
; CHECK-NOT: alloca
%cast = getelementptr [10 x i8]* %storage, i32 0, i32 0 ; <i8*> [#uses=1]
%tramp = call i8* @llvm.init.trampoline( i8* %cast, i8* bitcast (void ()* @test11f to i8*), i8* null ) ; <i8*> [#uses=1]
; CHECK-NOT: trampoline
ret void
; CHECK: ret void
}
; PR2599 - load -> store to same address.
define void @test12({ i32, i32 }* %x) nounwind {
%tmp4 = getelementptr { i32, i32 }* %x, i32 0, i32 0
%tmp5 = load i32* %tmp4, align 4
%tmp7 = getelementptr { i32, i32 }* %x, i32 0, i32 1
%tmp8 = load i32* %tmp7, align 4
%tmp17 = sub i32 0, %tmp8
store i32 %tmp5, i32* %tmp4, align 4
store i32 %tmp17, i32* %tmp7, align 4
ret void
; CHECK: @test12
; CHECK-NOT: tmp5
; CHECK: ret void
}
; %P doesn't escape, the DEAD instructions should be removed.
declare void @test13f()
define i32* @test13() {
%p = tail call i8* @malloc(i32 4)
%P = bitcast i8* %p to i32*
%DEAD = load i32* %P
%DEAD2 = add i32 %DEAD, 1
store i32 %DEAD2, i32* %P
call void @test13f( )
store i32 0, i32* %P
ret i32* %P
; CHECK: @test13()
; CHECK-NEXT: malloc
; CHECK-NEXT: bitcast
; CHECK-NEXT: call void
}
declare noalias i8* @malloc(i32)
define void @test14(i32* %Q) {
%P = alloca i32
%DEAD = load i32* %Q
store i32 %DEAD, i32* %P
ret void
; CHECK: @test14
; CHECK-NEXT: ret void
}
; PR8701
;; Fully dead overwrite of memcpy.
define void @test15(i8* %P, i8* %Q) nounwind ssp {
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
ret void
; CHECK: @test15
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: ret
}
;; Full overwrite of smaller memcpy.
define void @test16(i8* %P, i8* %Q) nounwind ssp {
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 8, i32 1, i1 false)
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
ret void
; CHECK: @test16
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: ret
}
;; Overwrite of memset by memcpy.
define void @test17(i8* %P, i8* noalias %Q) nounwind ssp {
tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 false)
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
ret void
; CHECK: @test17
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: ret
}
; Should not delete the volatile memset.
define void @test17v(i8* %P, i8* %Q) nounwind ssp {
tail call void @llvm.memset.p0i8.i64(i8* %P, i8 42, i64 8, i32 1, i1 true)
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
ret void
; CHECK: @test17v
; CHECK-NEXT: call void @llvm.memset
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: ret
}
; PR8728
; Do not delete instruction where possible situation is:
; A = B
; A = A
define void @test18(i8* %P, i8* %Q, i8* %R) nounwind ssp {
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %Q, i64 12, i32 1, i1 false)
tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %P, i8* %R, i64 12, i32 1, i1 false)
ret void
; CHECK: @test18
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: ret
}
; The store here is not dead because the byval call reads it.
declare void @test19f({i32}* byval align 4 %P)
define void @test19({i32} * nocapture byval align 4 %arg5) nounwind ssp {
bb:
%tmp7 = getelementptr inbounds {i32}* %arg5, i32 0, i32 0
store i32 912, i32* %tmp7
call void @test19f({i32}* byval align 4 %arg5)
ret void
; CHECK: @test19(
; CHECK: store i32 912
; CHECK: call void @test19f
}
define void @test20() {
%m = call i8* @malloc(i32 24)
store i8 0, i8* %m
ret void
}
; CHECK: @test20
; CHECK-NEXT: ret void