Index: llvm/test/Transforms/SimplifyCFG/merge-phis-in-switch.ll =================================================================== --- /dev/null +++ llvm/test/Transforms/SimplifyCFG/merge-phis-in-switch.ll @@ -0,0 +1,335 @@ +; 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 [[CASE01]] +; CHECK: case01: +; CHECK-NEXT: [[PHI1:%.*]] = phi i8 [ 2, [[CASE1]] ], [ 1, [[START:%.*]] ] +; CHECK-NEXT: br label [[END]] +; CHECK: end: +; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ [[PHI1]], [[CASE01]] ], [ 3, [[START]] ] +; 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 [[CASE012]] +; CHECK: case2: +; CHECK-NEXT: br label [[CASE012]] +; CHECK: case012: +; CHECK-NEXT: [[PHI1:%.*]] = phi i8 [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[START:%.*]] ] +; 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] + 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 [[CASE012]] +; CHECK: case2: +; CHECK-NEXT: br label [[CASE012]] +; CHECK: case012: +; CHECK-NEXT: [[PHI1_1:%.*]] = phi i8 [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[START:%.*]] ] +; CHECK-NEXT: [[PHI1_2:%.*]] = phi i8 [ 6, [[CASE2]] ], [ 5, [[CASE1]] ], [ 4, [[START]] ] +; CHECK-NEXT: br label [[END]] +; CHECK: end: +; CHECK-NEXT: [[PHI2_1:%.*]] = phi i8 [ [[PHI1_1]], [[CASE012]] ], [ 4, [[START]] ] +; CHECK-NEXT: [[PHI2_2:%.*]] = phi i8 [ [[PHI1_1]], [[CASE012]] ], [ 5, [[START]] ] +; CHECK-NEXT: [[PHI2_3:%.*]] = phi i8 [ [[PHI1_2]], [[CASE012]] ], [ 3, [[START]] ] +; 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 [[CASE0123]] +; CHECK: case1: +; CHECK-NEXT: br label [[CASE0123]] +; CHECK: case2: +; CHECK-NEXT: br label [[CASE0123]] +; CHECK: case0123: +; CHECK-NEXT: [[PHI1:%.*]] = phi i8 [ 4, [[START:%.*]] ], [ 3, [[CASE2]] ], [ 2, [[CASE1]] ], [ 1, [[CASE0]] ] +; CHECK-NEXT: br label [[CASE01234]] +; CHECK: case01234: +; CHECK-NEXT: [[PHI2:%.*]] = phi i8 [ [[PHI1]], [[CASE0123]] ], [ 5, [[START]] ] +; CHECK-NEXT: br label [[END]] +; CHECK: end: +; CHECK-NEXT: [[PHI3:%.*]] = phi i8 [ [[PHI2]], [[CASE01234]] ], [ 6, [[START]] ] +; 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 [[CASE012]] +; CHECK: case1: +; CHECK-NEXT: br label [[CASE012]] +; CHECK: case012: +; CHECK-NEXT: [[PHI123:%.*]] = phi i8 [ 3, [[START:%.*]] ], [ 2, [[CASE1]] ], [ 1, [[CASE0]] ] +; CHECK-NEXT: br label [[CASE0123456]] +; CHECK: case3: +; CHECK-NEXT: br label [[CASE345]] +; CHECK: case4: +; CHECK-NEXT: br label [[CASE345]] +; CHECK: case345: +; CHECK-NEXT: [[PHI456:%.*]] = phi i8 [ 6, [[START]] ], [ 5, [[CASE4]] ], [ 4, [[CASE3]] ] +; CHECK-NEXT: br label [[CASE0123456]] +; CHECK: case0123456: +; CHECK-NEXT: [[PHI1234567:%.*]] = phi i8 [ 7, [[START]] ], [ [[PHI456]], [[CASE345]] ], [ [[PHI123]], [[CASE012]] ] +; 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 +}