llvm-6502/test/Transforms/JumpThreading/basic.ll
Chris Lattner f3183f6da6 Make jump threading eliminate blocks that just contain phi nodes,
debug intrinsics, and an unconditional branch when possible.  This
reuses the TryToSimplifyUncondBranchFromEmptyBlock function split
out of simplifycfg.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86722 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 21:40:01 +00:00

248 lines
3.9 KiB
LLVM

; RUN: opt < %s -jump-threading -S | FileCheck %s
declare i32 @f1()
declare i32 @f2()
declare void @f3()
define i32 @test1(i1 %cond) {
; CHECK: @test1
br i1 %cond, label %T1, label %F1
T1:
%v1 = call i32 @f1()
br label %Merge
F1:
%v2 = call i32 @f2()
br label %Merge
Merge:
%A = phi i1 [true, %T1], [false, %F1]
%B = phi i32 [%v1, %T1], [%v2, %F1]
br i1 %A, label %T2, label %F2
T2:
; CHECK: T2:
; CHECK: ret i32 %v1
call void @f3()
ret i32 %B
F2:
; CHECK: F2:
; CHECK: ret i32 %v2
ret i32 %B
}
;; cond is known false on Entry -> F1 edge!
define i32 @test2(i1 %cond) {
; CHECK: @test2
Entry:
br i1 %cond, label %T1, label %F1
T1:
; CHECK: %v1 = call i32 @f1()
; CHECK: ret i32 47
%v1 = call i32 @f1()
br label %Merge
F1:
br i1 %cond, label %Merge, label %F2
Merge:
%B = phi i32 [47, %T1], [192, %F1]
ret i32 %B
F2:
call void @f3()
ret i32 12
}
; Undef handling.
define i32 @test3(i1 %cond) {
; CHECK: @test3
; CHECK-NEXT: T1:
; CHECK-NEXT: ret i32 42
br i1 undef, label %T1, label %F1
T1:
ret i32 42
F1:
ret i32 17
}
define i32 @test4(i1 %cond, i1 %cond2) {
; CHECK: @test4
br i1 %cond, label %T1, label %F1
T1:
; CHECK: %v1 = call i32 @f1()
; CHECK-NEXT: br label %T
%v1 = call i32 @f1()
br label %Merge
F1:
%v2 = call i32 @f2()
; CHECK: %v2 = call i32 @f2()
; CHECK-NEXT: br i1 %cond2,
br label %Merge
Merge:
%A = phi i1 [undef, %T1], [%cond2, %F1]
%B = phi i32 [%v1, %T1], [%v2, %F1]
br i1 %A, label %T2, label %F2
T2:
call void @f3()
ret i32 %B
F2:
ret i32 %B
}
;; This tests that the branch in 'merge' can be cloned up into T1.
define i32 @test5(i1 %cond, i1 %cond2) {
; CHECK: @test5
br i1 %cond, label %T1, label %F1
T1:
; CHECK: T1:
; CHECK-NEXT: %v1 = call i32 @f1()
; CHECK-NEXT: %cond3 = icmp eq i32 %v1, 412
; CHECK-NEXT: br i1 %cond3, label %T2, label %F2
%v1 = call i32 @f1()
%cond3 = icmp eq i32 %v1, 412
br label %Merge
F1:
%v2 = call i32 @f2()
br label %Merge
Merge:
%A = phi i1 [%cond3, %T1], [%cond2, %F1]
%B = phi i32 [%v1, %T1], [%v2, %F1]
br i1 %A, label %T2, label %F2
T2:
call void @f3()
ret i32 %B
F2:
ret i32 %B
}
;; Lexically duplicated conditionals should be threaded.
define i32 @test6(i32 %A) {
; CHECK: @test6
%tmp455 = icmp eq i32 %A, 42
br i1 %tmp455, label %BB1, label %BB2
BB2:
; CHECK: call i32 @f1()
; CHECK-NEXT: call void @f3()
; CHECK-NEXT: ret i32 4
call i32 @f1()
br label %BB1
BB1:
%tmp459 = icmp eq i32 %A, 42
br i1 %tmp459, label %BB3, label %BB4
BB3:
call i32 @f2()
ret i32 3
BB4:
call void @f3()
ret i32 4
}
;; This tests that the branch in 'merge' can be cloned up into T1.
;; rdar://7367025
define i32 @test7(i1 %cond, i1 %cond2) {
Entry:
; CHECK: @test7
%v1 = call i32 @f1()
br i1 %cond, label %Merge, label %F1
F1:
%v2 = call i32 @f2()
br label %Merge
Merge:
%B = phi i32 [%v1, %Entry], [%v2, %F1]
%M = icmp ne i32 %B, %v1
%N = icmp eq i32 %B, 47
%O = and i1 %M, %N
br i1 %O, label %T2, label %F2
; CHECK: Merge:
; CHECK-NOT: phi
; CHECK-NEXT: %v2 = call i32 @f2()
T2:
call void @f3()
ret i32 %B
F2:
ret i32 %B
; CHECK: F2:
; CHECK-NEXT: phi i32
}
declare i1 @test8a()
define i32 @test8b(i1 %cond, i1 %cond2) {
; CHECK: @test8b
T0:
%A = call i1 @test8a()
br i1 %A, label %T1, label %F1
; CHECK: T0:
; CHECK-NEXT: call
; CHECK-NEXT: br i1 %A, label %T1, label %Y
T1:
%B = call i1 @test8a()
br i1 %B, label %T2, label %F1
; CHECK: T1:
; CHECK-NEXT: call
; CHECK-NEXT: br i1 %B, label %T2, label %Y
T2:
%C = call i1 @test8a()
br i1 %cond, label %T3, label %F1
; CHECK: T2:
; CHECK-NEXT: call
; CHECK-NEXT: br i1 %cond, label %T3, label %Y
T3:
ret i32 0
F1:
%D = phi i32 [0, %T0], [0, %T1], [1, %T2]
%E = icmp eq i32 %D, 1
%F = and i1 %E, %cond
br i1 %F, label %X, label %Y
X:
call i1 @test8a()
ret i32 1
Y:
ret i32 2
}