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llvm-project/llvm/test/Transforms/SimplifyCFG/indirectbr.ll

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Teach SimplifyCFG how to simplify indirectbr instructions. - Eliminate redundant successors. - Convert an indirectbr with one successor into a direct branch. Also, generalize SimplifyCFG to be able to be run on a function entry block. It knows quite a few simplifications which are applicable to the entry block, and it only needs a few checks to avoid trouble with the entry block. llvm-svn: 111060
2010-08-14 08:29:42 +08:00
; RUN: opt -S -simplifycfg < %s | FileCheck %s
; SimplifyCFG should eliminate redundant indirectbr edges.
; CHECK: indbrtest0
; CHECK: indirectbr i8* %t, [label %BB0, label %BB1, label %BB2]
; CHECK: %x = phi i32 [ 0, %BB0 ], [ 1, %entry ]
declare void @foo()
declare void @A()
declare void @B(i32)
declare void @C()
define void @indbrtest0(i8** %P, i8** %Q) {
entry:
store i8* blockaddress(@indbrtest0, %BB0), i8** %P
store i8* blockaddress(@indbrtest0, %BB1), i8** %P
store i8* blockaddress(@indbrtest0, %BB2), i8** %P
call void @foo()
%t = load i8** %Q
indirectbr i8* %t, [label %BB0, label %BB1, label %BB2, label %BB0, label %BB1, label %BB2]
BB0:
call void @A()
br label %BB1
BB1:
%x = phi i32 [ 0, %BB0 ], [ 1, %entry ], [ 1, %entry ]
call void @B(i32 %x)
ret void
BB2:
call void @C()
ret void
}
; SimplifyCFG should convert the indirectbr into a directbr. It would be even
; better if it removed the branch altogether, but simplifycfdg currently misses
; that because the predecessor is the entry block.
; CHECK: indbrtest1
; CHECK: br label %BB0
define void @indbrtest1(i8** %P, i8** %Q) {
entry:
store i8* blockaddress(@indbrtest1, %BB0), i8** %P
call void @foo()
%t = load i8** %Q
indirectbr i8* %t, [label %BB0, label %BB0]
BB0:
call void @A()
ret void
}
Instead, teach SimplifyCFG to trim non-address-taken blocks from indirectbr destination lists. llvm-svn: 111122
2010-08-16 22:41:14 +08:00
; SimplifyCFG should notice that BB0 does not have its address taken and
; remove it from entry's successor list.
; CHECK: indbrtest2
; CHECK: entry:
; CHECK-NEXT: unreachable
define void @indbrtest2(i8* %t) {
entry:
indirectbr i8* %t, [label %BB0, label %BB0]
BB0:
ret void
}
Teach SimplifyCFG to turn (indirectbr (select cond, blockaddress(@fn, BlockA), blockaddress(@fn, BlockB))) into (br cond, BlockA, BlockB). llvm-svn: 120943
2010-12-06 02:29:03 +08:00
; Make sure the blocks in the next few tests aren't trivially removable as
; successors by taking their addresses.
@anchor = constant [13 x i8*] [
i8* blockaddress(@indbrtest3, %L1), i8* blockaddress(@indbrtest3, %L2), i8* blockaddress(@indbrtest3, %L3),
i8* blockaddress(@indbrtest4, %L1), i8* blockaddress(@indbrtest4, %L2), i8* blockaddress(@indbrtest4, %L3),
i8* blockaddress(@indbrtest5, %L1), i8* blockaddress(@indbrtest5, %L2), i8* blockaddress(@indbrtest5, %L3), i8* blockaddress(@indbrtest5, %L4),
i8* blockaddress(@indbrtest6, %L1), i8* blockaddress(@indbrtest6, %L2), i8* blockaddress(@indbrtest6, %L3)
]
; SimplifyCFG should turn the indirectbr into a conditional branch on the
; condition of the select.
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @indbrtest3(
Teach SimplifyCFG to turn (indirectbr (select cond, blockaddress(@fn, BlockA), blockaddress(@fn, BlockB))) into (br cond, BlockA, BlockB). llvm-svn: 120943
2010-12-06 02:29:03 +08:00
; CHECK-NEXT: entry:
; CHECK-NEXT: br i1 %cond, label %L1, label %L2
; CHECK-NOT: indirectbr
; CHECK-NOT: br
; CHECK-NOT: L3:
define void @indbrtest3(i1 %cond, i8* %address) nounwind {
entry:
%indirect.goto.dest = select i1 %cond, i8* blockaddress(@indbrtest3, %L1), i8* blockaddress(@indbrtest3, %L2)
indirectbr i8* %indirect.goto.dest, [label %L1, label %L2, label %L3]
L1:
call void @A()
ret void
L2:
call void @C()
ret void
L3:
call void @foo()
ret void
}
; SimplifyCFG should turn the indirectbr into an unconditional branch to the
; only possible destination.
; As in @indbrtest1, it should really remove the branch entirely, but it doesn't
; because it's in the entry block.
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @indbrtest4(
Teach SimplifyCFG to turn (indirectbr (select cond, blockaddress(@fn, BlockA), blockaddress(@fn, BlockB))) into (br cond, BlockA, BlockB). llvm-svn: 120943
2010-12-06 02:29:03 +08:00
; CHECK-NEXT: entry:
; CHECK-NEXT: br label %L1
define void @indbrtest4(i1 %cond) nounwind {
entry:
%indirect.goto.dest = select i1 %cond, i8* blockaddress(@indbrtest4, %L1), i8* blockaddress(@indbrtest4, %L1)
indirectbr i8* %indirect.goto.dest, [label %L1, label %L2, label %L3]
L1:
call void @A()
ret void
L2:
call void @C()
ret void
L3:
call void @foo()
ret void
}
; SimplifyCFG should turn the indirectbr into an unreachable because neither
; destination is listed as a successor.
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @indbrtest5(
Teach SimplifyCFG to turn (indirectbr (select cond, blockaddress(@fn, BlockA), blockaddress(@fn, BlockB))) into (br cond, BlockA, BlockB). llvm-svn: 120943
2010-12-06 02:29:03 +08:00
; CHECK-NEXT: entry:
; CHECK-NEXT: unreachable
; CHECK-NEXT: }
define void @indbrtest5(i1 %cond, i8* %anchor) nounwind {
entry:
%indirect.goto.dest = select i1 %cond, i8* blockaddress(@indbrtest5, %L1), i8* blockaddress(@indbrtest5, %L2)
; This needs to have more than one successor for this test, otherwise it gets
; replaced with an unconditional branch to the single successor.
indirectbr i8* %indirect.goto.dest, [label %L3, label %L4]
L1:
call void @A()
ret void
L2:
call void @C()
ret void
L3:
call void @foo()
ret void
L4:
call void @foo()
; This keeps blockaddresses not otherwise listed as successors from being zapped
; before SimplifyCFG even looks at the indirectbr.
indirectbr i8* %anchor, [label %L1, label %L2]
}
; The same as above, except the selected addresses are equal.
Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. This update was done with the following bash script: find test/Transforms -name "*.ll" | \ while read NAME; do echo "$NAME" if ! grep -q "^; *RUN: *llc" $NAME; then TEMP=`mktemp -t temp` cp $NAME $TEMP sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \ while read FUNC; do sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP done mv $TEMP $NAME fi done llvm-svn: 186268
2013-07-14 09:42:54 +08:00
; CHECK-LABEL: @indbrtest6(
Teach SimplifyCFG to turn (indirectbr (select cond, blockaddress(@fn, BlockA), blockaddress(@fn, BlockB))) into (br cond, BlockA, BlockB). llvm-svn: 120943
2010-12-06 02:29:03 +08:00
; CHECK-NEXT: entry:
; CHECK-NEXT: unreachable
; CHECK-NEXT: }
define void @indbrtest6(i1 %cond, i8* %anchor) nounwind {
entry:
%indirect.goto.dest = select i1 %cond, i8* blockaddress(@indbrtest6, %L1), i8* blockaddress(@indbrtest6, %L1)
; This needs to have more than one successor for this test, otherwise it gets
; replaced with an unconditional branch to the single successor.
indirectbr i8* %indirect.goto.dest, [label %L2, label %L3]
L1:
call void @A()
ret void
L2:
call void @C()
ret void
L3:
call void @foo()
; This keeps blockaddresses not otherwise listed as successors from being zapped
; before SimplifyCFG even looks at the indirectbr.
indirectbr i8* %anchor, [label %L1, label %L2]
}
If the block that we're threading through is jumped to by an indirect branch, then we don't want to set the destination in the indirect branch to the destination. This is because the indirect branch needs its destinations to have had their block addresses taken. This isn't so of the new critical edge that's split during this process. If it turns out that the destination block has only one predecessor, and that being a BB with an indirect branch, then it won't be marked as 'used' and may be removed. PR10072 llvm-svn: 132638
2011-06-04 17:42:04 +08:00
; PR10072
@xblkx.bbs = internal unnamed_addr constant [9 x i8*] [i8* blockaddress(@indbrtest7, %xblkx.begin), i8* blockaddress(@indbrtest7, %xblkx.begin3), i8* blockaddress(@indbrtest7, %xblkx.begin4), i8* blockaddress(@indbrtest7, %xblkx.begin5), i8* blockaddress(@indbrtest7, %xblkx.begin6), i8* blockaddress(@indbrtest7, %xblkx.begin7), i8* blockaddress(@indbrtest7, %xblkx.begin8), i8* blockaddress(@indbrtest7, %xblkx.begin9), i8* blockaddress(@indbrtest7, %xblkx.end)]
define void @indbrtest7() {
escape-string.top:
%xval202x = call i32 @xfunc5x()
br label %xlab5x
xlab8x: ; preds = %xlab5x
%xvaluex = call i32 @xselectorx()
%xblkx.x = getelementptr [9 x i8*]* @xblkx.bbs, i32 0, i32 %xvaluex
%xblkx.load = load i8** %xblkx.x
indirectbr i8* %xblkx.load, [label %xblkx.begin, label %xblkx.begin3, label %xblkx.begin4, label %xblkx.begin5, label %xblkx.begin6, label %xblkx.begin7, label %xblkx.begin8, label %xblkx.begin9, label %xblkx.end]
xblkx.begin:
br label %xblkx.end
xblkx.begin3:
br label %xblkx.end
xblkx.begin4:
br label %xblkx.end
xblkx.begin5:
br label %xblkx.end
xblkx.begin6:
br label %xblkx.end
xblkx.begin7:
br label %xblkx.end
xblkx.begin8:
br label %xblkx.end
xblkx.begin9:
br label %xblkx.end
xblkx.end:
%yes.0 = phi i1 [ false, %xblkx.begin ], [ true, %xlab8x ], [ false, %xblkx.begin9 ], [ false, %xblkx.begin8 ], [ false, %xblkx.begin7 ], [ false, %xblkx.begin6 ], [ false, %xblkx.begin5 ], [ true, %xblkx.begin4 ], [ false, %xblkx.begin3 ]
br i1 %yes.0, label %v2j, label %xlab17x
v2j:
; CHECK: %xunusedx = call i32 @xactionx()
%xunusedx = call i32 @xactionx()
br label %xlab4x
xlab17x:
br label %xlab4x
xlab4x:
%incr19 = add i32 %xval704x.0, 1
br label %xlab5x
xlab5x:
%xval704x.0 = phi i32 [ 0, %escape-string.top ], [ %incr19, %xlab4x ]
%xval10x = icmp ult i32 %xval704x.0, %xval202x
br i1 %xval10x, label %xlab8x, label %xlab9x
xlab9x:
ret void
}
declare i32 @xfunc5x()
declare i8 @xfunc7x()
declare i32 @xselectorx()
declare i32 @xactionx()