132 lines
3.5 KiB
LLVM
132 lines
3.5 KiB
LLVM
; RUN: opt < %s -simplifycfg -S > %t
|
|
; RUN: not grep "^BB.tomerge" %t
|
|
; RUN: grep "^BB.nomerge" %t | count 4
|
|
|
|
; ModuleID = '<stdin>'
|
|
declare i1 @foo()
|
|
|
|
declare i1 @bar(i32)
|
|
|
|
; This function can't be merged
|
|
define void @a() {
|
|
entry:
|
|
br label %BB.nomerge
|
|
|
|
BB.nomerge: ; preds = %Common, %entry
|
|
; This phi has a conflicting value (0) with below phi (2), so blocks
|
|
; can't be merged.
|
|
%a = phi i32 [ 1, %entry ], [ 0, %Common ] ; <i32> [#uses=1]
|
|
br label %Succ
|
|
|
|
Succ: ; preds = %Common, %BB.nomerge
|
|
%b = phi i32 [ %a, %BB.nomerge ], [ 2, %Common ] ; <i32> [#uses=0]
|
|
%conde = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %conde, label %Common, label %Exit
|
|
|
|
Common: ; preds = %Succ
|
|
%cond = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %cond, label %BB.nomerge, label %Succ
|
|
|
|
Exit: ; preds = %Succ
|
|
ret void
|
|
}
|
|
|
|
; This function can't be merged
|
|
define void @b() {
|
|
entry:
|
|
br label %BB.nomerge
|
|
|
|
BB.nomerge: ; preds = %Common, %entry
|
|
br label %Succ
|
|
|
|
Succ: ; preds = %Common, %BB.nomerge
|
|
; This phi has confliction values for Common and (through BB) Common,
|
|
; blocks can't be merged
|
|
%b = phi i32 [ 1, %BB.nomerge ], [ 2, %Common ] ; <i32> [#uses=0]
|
|
%conde = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %conde, label %Common, label %Exit
|
|
|
|
Common: ; preds = %Succ
|
|
%cond = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %cond, label %BB.nomerge, label %Succ
|
|
|
|
Exit: ; preds = %Succ
|
|
ret void
|
|
}
|
|
|
|
; This function can't be merged (for keeping canonical loop structures)
|
|
define void @c() {
|
|
entry:
|
|
br label %BB.nomerge
|
|
|
|
BB.nomerge: ; preds = %Common, %entry
|
|
br label %Succ
|
|
|
|
Succ: ; preds = %Common, %BB.tomerge, %Pre-Exit
|
|
; This phi has identical values for Common and (through BB) Common,
|
|
; blocks can't be merged
|
|
%b = phi i32 [ 1, %BB.nomerge ], [ 1, %Common ], [ 2, %Pre-Exit ]
|
|
%conde = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %conde, label %Common, label %Pre-Exit
|
|
|
|
Common: ; preds = %Succ
|
|
%cond = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %cond, label %BB.nomerge, label %Succ
|
|
|
|
Pre-Exit: ; preds = %Succ
|
|
; This adds a backedge, so the %b phi node gets a third branch and is
|
|
; not completely trivial
|
|
%cond2 = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %cond2, label %Succ, label %Exit
|
|
|
|
Exit: ; preds = %Pre-Exit
|
|
ret void
|
|
}
|
|
|
|
; This function can't be merged (for keeping canonical loop structures)
|
|
define void @d() {
|
|
entry:
|
|
br label %BB.nomerge
|
|
|
|
BB.nomerge: ; preds = %Common, %entry
|
|
; This phi has a matching value (0) with below phi (0), so blocks
|
|
; can be merged.
|
|
%a = phi i32 [ 1, %entry ], [ 0, %Common ] ; <i32> [#uses=1]
|
|
br label %Succ
|
|
|
|
Succ: ; preds = %Common, %BB.tomerge
|
|
%b = phi i32 [ %a, %BB.nomerge ], [ 0, %Common ] ; <i32> [#uses=0]
|
|
%conde = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %conde, label %Common, label %Exit
|
|
|
|
Common: ; preds = %Succ
|
|
%cond = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %cond, label %BB.nomerge, label %Succ
|
|
|
|
Exit: ; preds = %Succ
|
|
ret void
|
|
}
|
|
|
|
; This function can be merged
|
|
define void @e() {
|
|
entry:
|
|
br label %Succ
|
|
|
|
Succ: ; preds = %Use, %entry
|
|
; This phi is used somewhere else than Succ, but this should not prevent
|
|
; merging this block
|
|
%a = phi i32 [ 1, %entry ], [ 0, %Use ] ; <i32> [#uses=1]
|
|
br label %BB.tomerge
|
|
|
|
BB.tomerge: ; preds = %BB.tomerge
|
|
%conde = call i1 @foo( ) ; <i1> [#uses=1]
|
|
br i1 %conde, label %Use, label %Exit
|
|
|
|
Use: ; preds = %Succ
|
|
%cond = call i1 @bar( i32 %a ) ; <i1> [#uses=1]
|
|
br i1 %cond, label %Succ, label %Exit
|
|
|
|
Exit: ; preds = %Use, %Succ
|
|
ret void
|
|
}
|