llvm-6502/test/Transforms/CorrelatedValuePropagation/basic.ll
Benjamin Kramer e8aa36a4af CVP: If we have a PHI with an incoming select, try to skip the select.
This is a common pattern with dyn_cast and similar constructs, when the
PHI no longer depends on the select it can often be turned into a simpler
construct or even get hoisted out of the loop.

PR15340.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175995 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-24 15:34:43 +00:00

202 lines
4.1 KiB
LLVM

; RUN: opt < %s -correlated-propagation -S | FileCheck %s
; PR2581
; CHECK: @test1
define i32 @test1(i1 %C) nounwind {
br i1 %C, label %exit, label %body
body: ; preds = %0
; CHECK-NOT: select
%A = select i1 %C, i32 10, i32 11 ; <i32> [#uses=1]
; CHECK: ret i32 11
ret i32 %A
exit: ; preds = %0
; CHECK: ret i32 10
ret i32 10
}
; PR4420
declare i1 @ext()
; CHECK: @test2
define i1 @test2() {
entry:
%cond = tail call i1 @ext() ; <i1> [#uses=2]
br i1 %cond, label %bb1, label %bb2
bb1: ; preds = %entry
%cond2 = tail call i1 @ext() ; <i1> [#uses=1]
br i1 %cond2, label %bb3, label %bb2
bb2: ; preds = %bb1, %entry
; CHECK-NOT: phi i1
%cond_merge = phi i1 [ %cond, %entry ], [ false, %bb1 ] ; <i1> [#uses=1]
; CHECK: ret i1 false
ret i1 %cond_merge
bb3: ; preds = %bb1
%res = tail call i1 @ext() ; <i1> [#uses=1]
; CHECK: ret i1 %res
ret i1 %res
}
; PR4855
@gv = internal constant i8 7
; CHECK: @test3
define i8 @test3(i8* %a) nounwind {
entry:
%cond = icmp eq i8* %a, @gv
br i1 %cond, label %bb2, label %bb
bb: ; preds = %entry
ret i8 0
bb2: ; preds = %entry
; CHECK: %should_be_const = load i8* @gv
%should_be_const = load i8* %a
ret i8 %should_be_const
}
; PR1757
; CHECK: @test4
define i32 @test4(i32) {
EntryBlock:
; CHECK: icmp sgt i32 %0, 2
%.demorgan = icmp sgt i32 %0, 2
br i1 %.demorgan, label %GreaterThanTwo, label %LessThanOrEqualToTwo
GreaterThanTwo:
; CHECK-NOT: icmp eq i32 %0, 2
icmp eq i32 %0, 2
; CHECK: br i1 false
br i1 %1, label %Impossible, label %NotTwoAndGreaterThanTwo
NotTwoAndGreaterThanTwo:
ret i32 2
Impossible:
ret i32 1
LessThanOrEqualToTwo:
ret i32 0
}
declare i32* @f(i32*)
define void @test5(i32* %x, i32* %y) {
; CHECK: @test5
entry:
%pre = icmp eq i32* %x, null
br i1 %pre, label %return, label %loop
loop:
%phi = phi i32* [ %sel, %loop ], [ %x, %entry ]
; CHECK: %phi = phi i32* [ %f, %loop ], [ %x, %entry ]
%f = tail call i32* @f(i32* %phi)
%cmp1 = icmp ne i32* %f, %y
%sel = select i1 %cmp1, i32* %f, i32* null
%cmp2 = icmp eq i32* %sel, null
br i1 %cmp2, label %return, label %loop
return:
ret void
}
define i32 @switch1(i32 %s) {
; CHECK: @switch1
entry:
%cmp = icmp slt i32 %s, 0
br i1 %cmp, label %negative, label %out
negative:
switch i32 %s, label %out [
; CHECK: switch i32 %s, label %out
i32 0, label %out
; CHECK-NOT: i32 0
i32 1, label %out
; CHECK-NOT: i32 1
i32 -1, label %next
; CHECK: i32 -1, label %next
i32 -2, label %next
; CHECK: i32 -2, label %next
i32 2, label %out
; CHECK-NOT: i32 2
i32 3, label %out
; CHECK-NOT: i32 3
]
out:
%p = phi i32 [ 1, %entry ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ], [ -1, %negative ]
ret i32 %p
next:
%q = phi i32 [ 0, %negative ], [ 0, %negative ]
ret i32 %q
}
define i32 @switch2(i32 %s) {
; CHECK: @switch2
entry:
%cmp = icmp sgt i32 %s, 0
br i1 %cmp, label %positive, label %out
positive:
switch i32 %s, label %out [
i32 0, label %out
i32 -1, label %next
i32 -2, label %next
]
; CHECK: br label %out
out:
%p = phi i32 [ -1, %entry ], [ 1, %positive ], [ 1, %positive ]
ret i32 %p
next:
%q = phi i32 [ 0, %positive ], [ 0, %positive ]
ret i32 %q
}
define i32 @switch3(i32 %s) {
; CHECK: @switch3
entry:
%cmp = icmp sgt i32 %s, 0
br i1 %cmp, label %positive, label %out
positive:
switch i32 %s, label %out [
i32 -1, label %out
i32 -2, label %next
i32 -3, label %next
]
; CHECK: br label %out
out:
%p = phi i32 [ -1, %entry ], [ 1, %positive ], [ 1, %positive ]
ret i32 %p
next:
%q = phi i32 [ 0, %positive ], [ 0, %positive ]
ret i32 %q
}
define void @switch4(i32 %s) {
; CHECK: @switch4
entry:
%cmp = icmp eq i32 %s, 0
br i1 %cmp, label %zero, label %out
zero:
switch i32 %s, label %out [
i32 0, label %next
i32 1, label %out
i32 -1, label %out
]
; CHECK: br label %next
out:
ret void
next:
ret void
}