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llvm-project/llvm/test/Transforms/SimplifyCFG/sink-common-code.ll

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SimplifyCFG: sink common codes from IF, ELSE blocks down to END block. We already have HoistThenElseCodeToIf, this patch implements SinkThenElseCodeToEnd. When END block has only two predecessors and each predecessor terminates with unconditional branches, we compare instructions in IF and ELSE blocks backwards and check whether we can sink the common instructions down. rdar://12191395 llvm-svn: 164325
2012-09-21 06:37:36 +08:00
; RUN: opt < %s -simplifycfg -S | FileCheck %s
define zeroext i1 @test1(i1 zeroext %flag, i32 %blksA, i32 %blksB, i32 %nblks) {
entry:
br i1 %flag, label %if.then, label %if.else
[SimplifyCFG] Revise common code sinking - Fix the case where more than 1 common instructions derived from the same operand cannot be sunk. When a pair of value has more than 1 derived values in both branches, only 1 derived value could be sunk. - Replace BB1 -> (BB2, PN) map with joint value map, i.e. map of (BB1, BB2) -> PN, which is more accurate to track common ops. llvm-svn: 224757
2014-12-23 16:26:55 +08:00
; CHECK-LABEL: test1
SimplifyCFG: sink common codes from IF, ELSE blocks down to END block. We already have HoistThenElseCodeToIf, this patch implements SinkThenElseCodeToEnd. When END block has only two predecessors and each predecessor terminates with unconditional branches, we compare instructions in IF and ELSE blocks backwards and check whether we can sink the common instructions down. rdar://12191395 llvm-svn: 164325
2012-09-21 06:37:36 +08:00
; CHECK: add
; CHECK: select
; CHECK: icmp
; CHECK-NOT: br
if.then:
%cmp = icmp uge i32 %blksA, %nblks
%frombool1 = zext i1 %cmp to i8
br label %if.end
if.else:
%add = add i32 %nblks, %blksB
%cmp2 = icmp ule i32 %add, %blksA
%frombool3 = zext i1 %cmp2 to i8
br label %if.end
if.end:
%obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.else ]
%tobool4 = icmp ne i8 %obeys.0, 0
ret i1 %tobool4
}
define zeroext i1 @test2(i1 zeroext %flag, i32 %blksA, i32 %blksB, i32 %nblks) {
entry:
br i1 %flag, label %if.then, label %if.else
[SimplifyCFG] Revise common code sinking - Fix the case where more than 1 common instructions derived from the same operand cannot be sunk. When a pair of value has more than 1 derived values in both branches, only 1 derived value could be sunk. - Replace BB1 -> (BB2, PN) map with joint value map, i.e. map of (BB1, BB2) -> PN, which is more accurate to track common ops. llvm-svn: 224757
2014-12-23 16:26:55 +08:00
; CHECK-LABEL: test2
SimplifyCFG: sink common codes from IF, ELSE blocks down to END block. We already have HoistThenElseCodeToIf, this patch implements SinkThenElseCodeToEnd. When END block has only two predecessors and each predecessor terminates with unconditional branches, we compare instructions in IF and ELSE blocks backwards and check whether we can sink the common instructions down. rdar://12191395 llvm-svn: 164325
2012-09-21 06:37:36 +08:00
; CHECK: add
; CHECK: select
; CHECK: icmp
; CHECK-NOT: br
if.then:
%cmp = icmp uge i32 %blksA, %nblks
%frombool1 = zext i1 %cmp to i8
br label %if.end
if.else:
%add = add i32 %nblks, %blksB
%cmp2 = icmp uge i32 %blksA, %add
%frombool3 = zext i1 %cmp2 to i8
br label %if.end
if.end:
%obeys.0 = phi i8 [ %frombool1, %if.then ], [ %frombool3, %if.else ]
%tobool4 = icmp ne i8 %obeys.0, 0
ret i1 %tobool4
}
[SimplifyCFG] Revise common code sinking - Fix the case where more than 1 common instructions derived from the same operand cannot be sunk. When a pair of value has more than 1 derived values in both branches, only 1 derived value could be sunk. - Replace BB1 -> (BB2, PN) map with joint value map, i.e. map of (BB1, BB2) -> PN, which is more accurate to track common ops. llvm-svn: 224757
2014-12-23 16:26:55 +08:00
declare i32 @foo(i32, i32) nounwind readnone
define i32 @test3(i1 zeroext %flag, i32 %x, i32 %y) {
entry:
br i1 %flag, label %if.then, label %if.else
if.then:
%x0 = call i32 @foo(i32 %x, i32 0) nounwind readnone
%y0 = call i32 @foo(i32 %x, i32 1) nounwind readnone
br label %if.end
if.else:
%x1 = call i32 @foo(i32 %y, i32 0) nounwind readnone
%y1 = call i32 @foo(i32 %y, i32 1) nounwind readnone
br label %if.end
if.end:
%xx = phi i32 [ %x0, %if.then ], [ %x1, %if.else ]
%yy = phi i32 [ %y0, %if.then ], [ %y1, %if.else ]
%ret = add i32 %xx, %yy
ret i32 %ret
}
; CHECK-LABEL: test3
; CHECK: select
; CHECK: call
; CHECK: call
; CHECK: add
; CHECK-NOT: br