32 changes: 32 additions & 0 deletions llvm/test/Transforms/SimplifyCFG/branch-fold.ll
View file
Original file line number Diff line number Diff line change
Expand Up @@ -114,3 +114,35 @@ bb0:
call void @foo()
ret void
}

define i8 @common_pred(i8 noundef %arg, i1 %c1, i1 %c2) {
; CHECK-LABEL: @common_pred(
; CHECK-NEXT: Pred:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: br i1 [[C1:%.*]], label [[COMMONPRED:%.*]], label [[SUCC:%.*]]
; CHECK: CommonPred:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[C2:%.*]], i8 4, i8 1
; CHECK-NEXT: br label [[SUCC]]
; CHECK: Succ:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 0, [[PRED:%.*]] ], [ [[SPEC_SELECT]], [[COMMONPRED]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
Pred:
call void @dummy()
br i1 %c1, label %CommonPred, label %BB

CommonPred:
call void @dummy()
br i1 %c2, label %Succ, label %BB

BB:
%phi1 = phi i8 [ 0, %Pred ], [1, %CommonPred]
br label %Succ

Succ:
%phi2 = phi i8 [ %phi1, %BB ], [ 4, %CommonPred ]
ret i8 %phi2
}

declare void @dummy()
327 changes: 327 additions & 0 deletions llvm/test/Transforms/SimplifyCFG/merge-phis-in-switch.ll
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,327 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 3
; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s

; Test a bunch of cases where the combination of phis in switch should be merged into one phi

declare void @use(i8)

define i8 @phis_of_switch_minimal(i8 noundef %arg) {
; CHECK-LABEL: define i8 @phis_of_switch_minimal
; CHECK-SAME: (i8 noundef [[ARG:%.*]]) {
; CHECK-NEXT: start:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 0, label [[CASE01:%.*]]
; CHECK-NEXT: i8 1, label [[CASE1:%.*]]
; CHECK-NEXT: i8 2, label [[END:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case1:
; CHECK-NEXT: br label [[END]]
; CHECK: case01:
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 3, [[START:%.*]] ], [ 2, [[CASE1]] ], [ 1, [[CASE01]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
start:
switch i8 %arg, label %unreachable [
i8 0, label %case01
i8 1, label %case1
i8 2, label %end
]
unreachable:
unreachable
case1:
br label %case01

case01:
%phi1 = phi i8 [ 2, %case1 ], [1, %start]
br label %end

end:
%phi2 = phi i8 [ %phi1, %case01 ], [ 3, %start ]
ret i8 %phi2
}

define i8 @phis_of_switch(i8 noundef %arg) {
; CHECK-LABEL: define i8 @phis_of_switch
; CHECK-SAME: (i8 noundef [[ARG:%.*]]) {
; CHECK-NEXT: start:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 0, label [[CASE012:%.*]]
; CHECK-NEXT: i8 1, label [[CASE1:%.*]]
; CHECK-NEXT: i8 2, label [[CASE2:%.*]]
; CHECK-NEXT: i8 3, label [[END:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case1:
; CHECK-NEXT: br label [[END]]
; CHECK: case2:
; CHECK-NEXT: br label [[END]]
; CHECK: case012:
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 4, [[START:%.*]] ], [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[CASE012]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
start:
switch i8 %arg, label %unreachable [
i8 0, label %case012
i8 1, label %case1
i8 2, label %case2
i8 3, label %end
]
unreachable:
unreachable
case1:
br label %case012

case2:
br label %case012

case012:
%phi1 = phi i8 [ 3, %case2 ], [ 2, %case1 ], [1, %start]
br label %end

end:
%phi2 = phi i8 [ %phi1, %case012 ], [ 4, %start ]
ret i8 %phi2
}

define i8 @multiple_phis_of_switch(i8 noundef %arg) {
; CHECK-LABEL: define i8 @multiple_phis_of_switch
; CHECK-SAME: (i8 noundef [[ARG:%.*]]) {
; CHECK-NEXT: start:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 0, label [[CASE012:%.*]]
; CHECK-NEXT: i8 1, label [[CASE1:%.*]]
; CHECK-NEXT: i8 2, label [[CASE2:%.*]]
; CHECK-NEXT: i8 3, label [[END:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case1:
; CHECK-NEXT: br label [[END]]
; CHECK: case2:
; CHECK-NEXT: br label [[END]]
; CHECK: case012:
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI2_1:%.*]] = phi i8 [ 4, [[START:%.*]] ], [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[CASE012]] ]
; CHECK-NEXT: [[PHI2_2:%.*]] = phi i8 [ 5, [[START]] ], [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[CASE012]] ]
; CHECK-NEXT: [[PHI2_3:%.*]] = phi i8 [ 3, [[START]] ], [ 6, [[CASE2]] ], [ 5, [[CASE1]] ], [ 4, [[CASE012]] ]
; CHECK-NEXT: call void @use(i8 [[PHI2_1]])
; CHECK-NEXT: call void @use(i8 [[PHI2_2]])
; CHECK-NEXT: call void @use(i8 [[PHI2_3]])
; CHECK-NEXT: ret i8 [[PHI2_1]]
;
start:
switch i8 %arg, label %unreachable [
i8 0, label %case012
i8 1, label %case1
i8 2, label %case2
i8 3, label %end
]
unreachable:
unreachable
case1:
br label %case012

case2:
br label %case012

case012:
%phi1_1 = phi i8 [ 3, %case2 ], [ 2, %case1 ], [1, %start]
%phi1_2 = phi i8 [ 6, %case2 ], [ 5, %case1 ], [4, %start]
br label %end

end:
%phi2_1 = phi i8 [ %phi1_1, %case012 ], [ 4, %start ]
%phi2_2 = phi i8 [ %phi1_1, %case012 ], [ 5, %start ]
%phi2_3 = phi i8 [ %phi1_2, %case012 ], [ 3, %start ]
call void @use(i8 %phi2_1)
call void @use(i8 %phi2_2)
call void @use(i8 %phi2_3)
ret i8 %phi2_1
}

define i8 @phis_of_switch_multiple_stage0(i8 noundef %arg) {
; CHECK-LABEL: define i8 @phis_of_switch_multiple_stage0
; CHECK-SAME: (i8 noundef [[ARG:%.*]]) {
; CHECK-NEXT: start:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 0, label [[CASE0:%.*]]
; CHECK-NEXT: i8 1, label [[CASE1:%.*]]
; CHECK-NEXT: i8 2, label [[CASE2:%.*]]
; CHECK-NEXT: i8 3, label [[CASE0123:%.*]]
; CHECK-NEXT: i8 4, label [[CASE01234:%.*]]
; CHECK-NEXT: i8 5, label [[END:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case0:
; CHECK-NEXT: br label [[END]]
; CHECK: case1:
; CHECK-NEXT: br label [[END]]
; CHECK: case2:
; CHECK-NEXT: br label [[END]]
; CHECK: case0123:
; CHECK-NEXT: br label [[END]]
; CHECK: case01234:
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI3:%.*]] = phi i8 [ 6, [[START:%.*]] ], [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[CASE0]] ], [ 4, [[CASE0123]] ], [ 5, [[CASE01234]] ]
; CHECK-NEXT: ret i8 [[PHI3]]
;
start:
switch i8 %arg, label %unreachable [
i8 0, label %case0
i8 1, label %case1
i8 2, label %case2
i8 3, label %case0123
i8 4, label %case01234
i8 5, label %end
]
unreachable:
unreachable

case0:
br label %case0123

case1:
br label %case0123

case2:
br label %case0123

case0123:
%phi1 = phi i8 [4, %start], [ 3, %case2 ], [ 2, %case1 ], [ 1, %case0 ]
br label %case01234

case01234:
%phi2 = phi i8 [ %phi1, %case0123 ], [ 5, %start ]
br label %end

end:
%phi3 = phi i8 [ %phi2, %case01234 ], [6, %start]
ret i8 %phi3
}

define i8 @phis_of_switch_multiple_stage1(i8 noundef %arg) {
; CHECK-LABEL: define i8 @phis_of_switch_multiple_stage1
; CHECK-SAME: (i8 noundef [[ARG:%.*]]) {
; CHECK-NEXT: start:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 0, label [[CASE0:%.*]]
; CHECK-NEXT: i8 1, label [[CASE1:%.*]]
; CHECK-NEXT: i8 2, label [[CASE012:%.*]]
; CHECK-NEXT: i8 3, label [[CASE3:%.*]]
; CHECK-NEXT: i8 4, label [[CASE4:%.*]]
; CHECK-NEXT: i8 5, label [[CASE345:%.*]]
; CHECK-NEXT: i8 6, label [[CASE0123456:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case0:
; CHECK-NEXT: br label [[CASE0123456]]
; CHECK: case1:
; CHECK-NEXT: br label [[CASE0123456]]
; CHECK: case012:
; CHECK-NEXT: br label [[CASE0123456]]
; CHECK: case3:
; CHECK-NEXT: br label [[CASE0123456]]
; CHECK: case4:
; CHECK-NEXT: br label [[CASE0123456]]
; CHECK: case345:
; CHECK-NEXT: br label [[CASE0123456]]
; CHECK: case0123456:
; CHECK-NEXT: [[PHI1234567:%.*]] = phi i8 [ 7, [[START:%.*]] ], [ 2, [[CASE1]] ], [ 1, [[CASE0]] ], [ 3, [[CASE012]] ], [ 5, [[CASE4]] ], [ 4, [[CASE3]] ], [ 6, [[CASE345]] ]
; CHECK-NEXT: ret i8 [[PHI1234567]]
;
start:
switch i8 %arg, label %unreachable [
i8 0, label %case0
i8 1, label %case1
i8 2, label %case012
i8 3, label %case3
i8 4, label %case4
i8 5, label %case345
i8 6, label %case0123456
]
unreachable:
unreachable
case0:
br label %case012

case1:
br label %case012

case012:
%phi123 = phi i8 [3, %start], [ 2, %case1 ], [ 1, %case0 ]
br label %case0123456

case3:
br label %case345

case4:
br label %case345

case345:
%phi456 = phi i8 [6, %start], [ 5, %case4 ], [ 4, %case3 ]
br label %case0123456

case0123456:
%phi1234567 = phi i8 [7, %start], [ %phi456, %case345 ], [ %phi123, %case012 ]
ret i8 %phi1234567

}

define i8 @phis_of_switch_extra_use_fail(i8 noundef %arg) {
; CHECK-LABEL: define i8 @phis_of_switch_extra_use_fail
; CHECK-SAME: (i8 noundef [[ARG:%.*]]) {
; CHECK-NEXT: start:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 0, label [[CASE012:%.*]]
; CHECK-NEXT: i8 1, label [[CASE1:%.*]]
; CHECK-NEXT: i8 2, label [[CASE2:%.*]]
; CHECK-NEXT: i8 3, label [[END:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case1:
; CHECK-NEXT: br label [[CASE012]]
; CHECK: case2:
; CHECK-NEXT: br label [[CASE012]]
; CHECK: case012:
; CHECK-NEXT: [[PHI1:%.*]] = phi i8 [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[START:%.*]] ]
; CHECK-NEXT: call void @use(i8 [[PHI1]])
; CHECK-NEXT: br label [[END]]
; CHECK: end:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ [[PHI1]], [[CASE012]] ], [ 4, [[START]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
start:
switch i8 %arg, label %unreachable [
i8 0, label %case012
i8 1, label %case1
i8 2, label %case2 i8 3, label %end
]
unreachable:
unreachable
case1:
br label %case012

case2:
br label %case012

case012:
%phi1 = phi i8 [ 3, %case2 ], [ 2, %case1 ], [1, %start]
call void @use(i8 %phi1)
br label %end

end:
%phi2 = phi i8 [ %phi1, %case012 ], [ 4, %start ]
ret i8 %phi2
}
279 changes: 274 additions & 5 deletions llvm/test/Transforms/SimplifyCFG/multiple-phis.ll
View file
Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2

; RUN: opt -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -keep-loops=false -S < %s | FileCheck %s
; RUN: opt -passes='simplifycfg<no-keep-loops>' -S < %s | FileCheck %s

Expand All @@ -7,21 +8,22 @@
; SimplifyCFG if-converts one of the phis, it should do both.

define i32 @upper_bound(ptr %r, i32 %high, i32 %k) nounwind {
; CHECK-LABEL: @upper_bound(
; CHECK-LABEL: define i32 @upper_bound
; CHECK-SAME: (ptr [[R:%.*]], i32 [[HIGH:%.*]], i32 [[K:%.*]]) #[[ATTR0:[0-9]+]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[WHILE_COND:%.*]]
; CHECK: while.cond:
; CHECK-NEXT: [[HIGH_ADDR_0:%.*]] = phi i32 [ [[HIGH:%.*]], [[ENTRY:%.*]] ], [ [[SPEC_SELECT:%.*]], [[WHILE_BODY:%.*]] ]
; CHECK-NEXT: [[HIGH_ADDR_0:%.*]] = phi i32 [ [[HIGH]], [[ENTRY:%.*]] ], [ [[SPEC_SELECT:%.*]], [[WHILE_BODY:%.*]] ]
; CHECK-NEXT: [[LOW_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[SPEC_SELECT1:%.*]], [[WHILE_BODY]] ]
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[LOW_0]], [[HIGH_ADDR_0]]
; CHECK-NEXT: br i1 [[CMP]], label [[WHILE_BODY]], label [[WHILE_END:%.*]]
; CHECK: while.body:
; CHECK-NEXT: [[ADD:%.*]] = add i32 [[LOW_0]], [[HIGH_ADDR_0]]
; CHECK-NEXT: [[DIV:%.*]] = udiv i32 [[ADD]], 2
; CHECK-NEXT: [[IDXPROM:%.*]] = zext i32 [[DIV]] to i64
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[R:%.*]], i64 [[IDXPROM]]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[R]], i64 [[IDXPROM]]
; CHECK-NEXT: [[TMP0:%.*]] = load i32, ptr [[ARRAYIDX]], align 4
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[K:%.*]], [[TMP0]]
; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i32 [[K]], [[TMP0]]
; CHECK-NEXT: [[ADD2:%.*]] = add i32 [[DIV]], 1
; CHECK-NEXT: [[SPEC_SELECT]] = select i1 [[CMP1]], i32 [[DIV]], i32 [[HIGH_ADDR_0]]
; CHECK-NEXT: [[SPEC_SELECT1]] = select i1 [[CMP1]], i32 [[LOW_0]], i32 [[ADD2]]
Expand Down Expand Up @@ -57,3 +59,270 @@ if.else: ; preds = %while.body
while.end: ; preds = %while.cond
ret i32 %low.0
}

define i32 @merge0(i1 %c1, i1 %c2, i1 %c3) {
; CHECK-LABEL: define i32 @merge0
; CHECK-SAME: (i1 [[C1:%.*]], i1 [[C2:%.*]], i1 [[C3:%.*]]) {
; CHECK-NEXT: j2:
; CHECK-NEXT: [[DOT:%.*]] = select i1 [[C2]], i32 0, i32 1
; CHECK-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[C3]], i32 2, i32 3
; CHECK-NEXT: [[PHI2:%.*]] = select i1 [[C1]], i32 [[DOT]], i32 [[SPEC_SELECT]]
; CHECK-NEXT: ret i32 [[PHI2]]
;
br i1 %c1, label %if1, label %else1

if1:
br i1 %c2, label %if2, label %else2

if2:
br label %j1 else2:
br label %j1

else1:
br i1 %c3, label %j1, label %j2

j1:
%phi1 = phi i32 [ 0, %if2 ], [ 1, %else2 ], [ 2, %else1 ]
br label %j2

j2:
%phi2 = phi i32 [ %phi1, %j1 ], [ 3, %else1 ]
ret i32 %phi2
}

define i8 @merge1(i8 noundef %arg, i1 %c1, i1 %c2) {
; CHECK-LABEL: define i8 @merge1
; CHECK-SAME: (i8 noundef [[ARG:%.*]], i1 [[C1:%.*]], i1 [[C2:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 -123, label [[CASE0:%.*]]
; CHECK-NEXT: i8 66, label [[SUCC:%.*]]
; CHECK-NEXT: i8 123, label [[CASE2:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case0:
; CHECK-NEXT: [[C1_NOT:%.*]] = xor i1 [[C1]], true
; CHECK-NEXT: [[C2_NOT:%.*]] = xor i1 [[C2]], true
; CHECK-NEXT: [[BRMERGE:%.*]] = select i1 [[C1_NOT]], i1 true, i1 [[C2_NOT]]
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 [[C1_NOT]], i8 0, i8 3
; CHECK-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[BRMERGE]], i8 [[DOTMUX]], i8 4
; CHECK-NEXT: br label [[SUCC]]
; CHECK: case2:
; CHECK-NEXT: br label [[SUCC]]
; CHECK: Succ:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 2, [[CASE2]] ], [ 1, [[ENTRY:%.*]] ], [ [[SPEC_SELECT]], [[CASE0]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
entry:
switch i8 %arg, label %unreachable [
i8 -123, label %case0
i8 66, label %case1
i8 123, label %case2
]

unreachable:
unreachable

case0:
br i1 %c1, label %CommonPred, label %BB

case1:
br label %BB

case2:
br label %BB

CommonPred:
br i1 %c2, label %Succ, label %BB

BB:
%phi1 = phi i8 [ 0, %case0 ], [1, %case1],[2, %case2],[3,%CommonPred]
br label %Succ

Succ:
%phi2 = phi i8 [ %phi1, %BB ], [ 4, %CommonPred ]
ret i8 %phi2
}

define i8 @merge1_unfoldable_one_block(i8 noundef %arg, i1 %c1, i1 %c2) {
; CHECK-LABEL: define i8 @merge1_unfoldable_one_block
; CHECK-SAME: (i8 noundef [[ARG:%.*]], i1 [[C1:%.*]], i1 [[C2:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 -123, label [[CASE0:%.*]]
; CHECK-NEXT: i8 66, label [[SUCC:%.*]]
; CHECK-NEXT: i8 123, label [[CASE2:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case0:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: [[C1_NOT:%.*]] = xor i1 [[C1]], true
; CHECK-NEXT: [[C2_NOT:%.*]] = xor i1 [[C2]], true
; CHECK-NEXT: [[BRMERGE:%.*]] = select i1 [[C1_NOT]], i1 true, i1 [[C2_NOT]]
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 [[C1_NOT]], i8 0, i8 3
; CHECK-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[BRMERGE]], i8 [[DOTMUX]], i8 4
; CHECK-NEXT: br label [[SUCC]]
; CHECK: case2:
; CHECK-NEXT: br label [[SUCC]]
; CHECK: Succ:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 2, [[CASE2]] ], [ 1, [[ENTRY:%.*]] ], [ [[SPEC_SELECT]], [[CASE0]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
entry:
switch i8 %arg, label %unreachable [
i8 -123, label %case0
i8 66, label %case1
i8 123, label %case2
]

unreachable:
unreachable

case0:
call void @dummy()
br i1 %c1, label %CommonPred, label %BB

case1:
br label %BB

case2:
br label %BB

CommonPred:
br i1 %c2, label %Succ, label %BB

BB:
%phi1 = phi i8 [ 0, %case0 ], [1, %case1],[2, %case2],[3,%CommonPred]
br label %Succ

Succ:
%phi2 = phi i8 [ %phi1, %BB ], [ 4, %CommonPred ]
ret i8 %phi2
}

define i8 @merge1_unfoldable_two_block(i8 noundef %arg, i1 %c1, i1 %c2) {
; CHECK-LABEL: define i8 @merge1_unfoldable_two_block
; CHECK-SAME: (i8 noundef [[ARG:%.*]], i1 [[C1:%.*]], i1 [[C2:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 -123, label [[CASE0:%.*]]
; CHECK-NEXT: i8 66, label [[CASE1:%.*]]
; CHECK-NEXT: i8 123, label [[SUCC:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case0:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: [[C1_NOT:%.*]] = xor i1 [[C1]], true
; CHECK-NEXT: [[C2_NOT:%.*]] = xor i1 [[C2]], true
; CHECK-NEXT: [[BRMERGE:%.*]] = select i1 [[C1_NOT]], i1 true, i1 [[C2_NOT]]
; CHECK-NEXT: [[DOTMUX:%.*]] = select i1 [[C1_NOT]], i8 0, i8 3
; CHECK-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[BRMERGE]], i8 [[DOTMUX]], i8 4
; CHECK-NEXT: br label [[SUCC]]
; CHECK: case1:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: br label [[SUCC]]
; CHECK: Succ:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 1, [[CASE1]] ], [ 2, [[ENTRY:%.*]] ], [ [[SPEC_SELECT]], [[CASE0]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
entry:
switch i8 %arg, label %unreachable [
i8 -123, label %case0
i8 66, label %case1
i8 123, label %case2
]

unreachable:
unreachable

case0:
call void @dummy()
br i1 %c1, label %CommonPred, label %BB

case1:
call void @dummy()
br label %BB

case2:
br label %BB

CommonPred:
br i1 %c2, label %Succ, label %BB

BB:
%phi1 = phi i8 [ 0, %case0 ], [1, %case1],[2, %case2],[3,%CommonPred]
br label %Succ

Succ:
%phi2 = phi i8 [ %phi1, %BB ], [ 4, %CommonPred ]
ret i8 %phi2
}

define i8 @merge1_unfoldable_all_block(i8 noundef %arg, i1 %c1, i1 %c2) {
; CHECK-LABEL: define i8 @merge1_unfoldable_all_block
; CHECK-SAME: (i8 noundef [[ARG:%.*]], i1 [[C1:%.*]], i1 [[C2:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: switch i8 [[ARG]], label [[UNREACHABLE:%.*]] [
; CHECK-NEXT: i8 -123, label [[CASE0:%.*]]
; CHECK-NEXT: i8 66, label [[CASE1:%.*]]
; CHECK-NEXT: i8 123, label [[CASE2:%.*]]
; CHECK-NEXT: ]
; CHECK: unreachable:
; CHECK-NEXT: unreachable
; CHECK: case0:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: br i1 [[C1]], label [[COMMONPRED:%.*]], label [[SUCC:%.*]]
; CHECK: case1:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: br label [[SUCC]]
; CHECK: case2:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: br label [[SUCC]]
; CHECK: CommonPred:
; CHECK-NEXT: call void @dummy()
; CHECK-NEXT: [[SPEC_SELECT:%.*]] = select i1 [[C2]], i8 4, i8 3
; CHECK-NEXT: br label [[SUCC]]
; CHECK: Succ:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 0, [[CASE0]] ], [ 1, [[CASE1]] ], [ 2, [[CASE2]] ], [ [[SPEC_SELECT]], [[COMMONPRED]] ]
; CHECK-NEXT: ret i8 [[PHI2]]
;
entry:
switch i8 %arg, label %unreachable [
i8 -123, label %case0
i8 66, label %case1
i8 123, label %case2
]

unreachable:
unreachable

case0:
call void @dummy()
br i1 %c1, label %CommonPred, label %BB

case1:
call void @dummy()
br label %BB

case2:
call void @dummy()
br label %BB

CommonPred:
call void @dummy()
br i1 %c2, label %Succ, label %BB

BB:
%phi1 = phi i8 [ 0, %case0 ], [1, %case1],[2, %case2],[3,%CommonPred]
br label %Succ

Succ:
%phi2 = phi i8 [ %phi1, %BB ], [ 4, %CommonPred ]
ret i8 %phi2
}

declare void @dummy()

3 changes: 3 additions & 0 deletions llvm/test/Transforms/SimplifyCFG/switch-simplify-crash2.ll
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,9 @@ define i8 @test() {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[LOOP2:%.*]]
; CHECK: loop2:
; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ 0, [[ENTRY:%.*]] ], [ [[SPEC_SELECT:%.*]], [[LOOP2]] ]
; CHECK-NEXT: [[COND:%.*]] = icmp eq i8 [[PHI2]], 0
; CHECK-NEXT: [[SPEC_SELECT]] = select i1 [[COND]], i8 0, i8 [[PHI2]]
; CHECK-NEXT: br label [[LOOP2]]
;
entry:
Expand Down