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