James Molloy 67ae135759 Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.
Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-20 16:04:27 +00:00

515 lines
8.6 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
; CHECK: call i32 @f2()
; CHECK-NEXT: ret i32 3
; CHECK: call i32 @f1()
; CHECK-NOT: br
; CHECK: call void @f3()
; CHECK-NOT: br
; CHECK: ret i32 4
BB2:
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
}
;;; Verify that we can handle constraint propagation through "xor x, 1".
define i32 @test9(i1 %cond, i1 %cond2) {
Entry:
; CHECK: @test9
%v1 = call i32 @f1()
br i1 %cond, label %Merge, label %F1
; CHECK: Entry:
; CHECK-NEXT: %v1 = call i32 @f1()
; CHECK-NEXT: br i1 %cond, label %F2, label %Merge
F1:
%v2 = call i32 @f2()
br label %Merge
Merge:
%B = phi i32 [%v1, %Entry], [%v2, %F1]
%M = icmp eq i32 %B, %v1
%M1 = xor i1 %M, 1
%N = icmp eq i32 %B, 47
%O = and i1 %M1, %N
br i1 %O, label %T2, label %F2
; CHECK: Merge:
; CHECK-NOT: phi
; CHECK-NEXT: %v2 = call i32 @f2()
T2:
%Q = zext i1 %M to i32
ret i32 %Q
F2:
ret i32 %B
; CHECK: F2:
; CHECK-NEXT: phi i32
}
; CHECK: @test10
declare i32 @test10f1()
declare i32 @test10f2()
declare void @test10f3()
;; Non-local condition threading.
define i32 @test10g(i1 %cond) {
; CHECK: @test10g
; CHECK-NEXT: br i1 %cond, label %T2, label %F2
br i1 %cond, label %T1, label %F1
T1:
%v1 = call i32 @test10f1()
br label %Merge
; CHECK: %v1 = call i32 @test10f1()
; CHECK-NEXT: call void @f3()
; CHECK-NEXT: ret i32 %v1
F1:
%v2 = call i32 @test10f2()
br label %Merge
Merge:
%B = phi i32 [%v1, %T1], [%v2, %F1]
br i1 %cond, label %T2, label %F2
T2:
call void @f3()
ret i32 %B
F2:
ret i32 %B
}
; Impossible conditional constraints should get threaded. BB3 is dead here.
define i32 @test11(i32 %A) {
; CHECK: @test11
; CHECK-NEXT: icmp
; CHECK-NEXT: br i1 %tmp455, label %BB4, label %BB2
%tmp455 = icmp eq i32 %A, 42
br i1 %tmp455, label %BB1, label %BB2
BB2:
; CHECK: call i32 @f1()
; CHECK-NEXT: ret i32 %C
%C = call i32 @f1()
ret i32 %C
BB1:
%tmp459 = icmp eq i32 %A, 43
br i1 %tmp459, label %BB3, label %BB4
BB3:
call i32 @f2()
ret i32 3
BB4:
call void @f3()
ret i32 4
}
;; Correlated value through boolean expression. GCC PR18046.
define void @test12(i32 %A) {
; CHECK: @test12
entry:
%cond = icmp eq i32 %A, 0
br i1 %cond, label %bb, label %bb1
; Should branch to the return block instead of through BB1.
; CHECK: entry:
; CHECK-NEXT: %cond = icmp eq i32 %A, 0
; CHECK-NEXT: br i1 %cond, label %bb1, label %return
bb:
%B = call i32 @test10f2()
br label %bb1
bb1:
%C = phi i32 [ %A, %entry ], [ %B, %bb ]
%cond4 = icmp eq i32 %C, 0
br i1 %cond4, label %bb2, label %return
; CHECK: bb1:
; CHECK-NEXT: %B = call i32 @test10f2()
; CHECK-NEXT: %cond4 = icmp eq i32 %B, 0
; CHECK-NEXT: br i1 %cond4, label %bb2, label %return
bb2:
%D = call i32 @test10f2()
ret void
return:
ret void
}
;; Duplicate condition to avoid xor of cond.
;; rdar://7391699
define i32 @test13(i1 %cond, i1 %cond2) {
Entry:
; CHECK: @test13
%v1 = call i32 @f1()
br i1 %cond, label %Merge, label %F1
F1:
br label %Merge
Merge:
%B = phi i1 [true, %Entry], [%cond2, %F1]
%C = phi i32 [192, %Entry], [%v1, %F1]
%M = icmp eq i32 %C, 192
%N = xor i1 %B, %M
br i1 %N, label %T2, label %F2
T2:
ret i32 123
F2:
ret i32 %v1
; CHECK: br i1 %cond, label %F2, label %Merge
; CHECK: Merge:
; CHECK-NEXT: %M = icmp eq i32 %v1, 192
; CHECK-NEXT: %N = xor i1 %cond2, %M
; CHECK-NEXT: br i1 %N, label %T2, label %F2
}
; CHECK: @test14
define i32 @test14(i32 %in) {
entry:
%A = icmp eq i32 %in, 0
; CHECK: br i1 %A, label %right_ret, label %merge
br i1 %A, label %left, label %right
; CHECK-NOT: left:
left:
br label %merge
; CHECK-NOT: right:
right:
%B = call i32 @f1()
br label %merge
merge:
; CHECK-NOT: %C = phi i32 [%in, %left], [%B, %right]
%C = phi i32 [%in, %left], [%B, %right]
%D = add i32 %C, 1
%E = icmp eq i32 %D, 2
br i1 %E, label %left_ret, label %right_ret
; CHECK: left_ret:
left_ret:
ret i32 0
right_ret:
ret i32 1
}
; PR5652
; CHECK: @test15
define i32 @test15(i32 %len) {
entry:
; CHECK: icmp ult i32 %len, 13
%tmp = icmp ult i32 %len, 13
br i1 %tmp, label %check, label %exit0
exit0:
ret i32 0
check:
%tmp9 = icmp ult i32 %len, 21
br i1 %tmp9, label %exit1, label %exit2
exit2:
; CHECK-NOT: ret i32 2
ret i32 2
exit1:
ret i32 1
; CHECK: }
}
; In this test we check that block duplication is inhibited by the presence
; of a function with the 'noduplicate' attribute.
declare void @g()
declare void @j()
declare void @k()
; CHECK: define void @h(i32 %p) {
define void @h(i32 %p) {
%x = icmp ult i32 %p, 5
br i1 %x, label %l1, label %l2
l1:
call void @j()
br label %l3
l2:
call void @k()
br label %l3
l3:
; CHECK: call void @g() noduplicate
; CHECK-NOT: call void @g() noduplicate
call void @g() noduplicate
%y = icmp ult i32 %p, 5
br i1 %y, label %l4, label %l5
l4:
call void @j()
ret void
l5:
call void @k()
ret void
; CHECK: }
}