; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -passes=simplifycfg --switch-to-lookup -S < %s | FileCheck %s target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" declare i1 @foo() ; https://alive2.llvm.org/ce/z/tuxLhJ define i1 @switch_lookup_with_small_i1(i64 %x) { ; CHECK-LABEL: @switch_lookup_with_small_i1( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[AND:%.*]] = and i64 [[X:%.*]], 15 ; CHECK-NEXT: [[SWITCH_CAST:%.*]] = trunc i64 [[AND]] to i16 ; CHECK-NEXT: [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i16 [[SWITCH_CAST]], 1 ; CHECK-NEXT: [[SWITCH_DOWNSHIFT:%.*]] = lshr i16 1030, [[SWITCH_SHIFTAMT]] ; CHECK-NEXT: [[SWITCH_MASKED:%.*]] = trunc i16 [[SWITCH_DOWNSHIFT]] to i1 ; CHECK-NEXT: ret i1 [[SWITCH_MASKED]] ; entry: %and = and i64 %x, 15 switch i64 %and, label %default [ i64 10, label %lor.end i64 1, label %lor.end i64 2, label %lor.end ] default: ; preds = %entry br label %lor.end lor.end: ; preds = %entry, %entry, %entry, %default %0 = phi i1 [ true, %entry ], [ false, %default ], [ true, %entry ], [ true, %entry ] ret i1 %0 } ; https://godbolt.org/z/sjbjorKon define i8 @switch_lookup_with_small_i8(i64 %x) { ; CHECK-LABEL: @switch_lookup_with_small_i8( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[REM:%.*]] = urem i64 [[X:%.*]], 5 ; CHECK-NEXT: [[SWITCH_CAST:%.*]] = trunc i64 [[REM]] to i40 ; CHECK-NEXT: [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i40 [[SWITCH_CAST]], 8 ; CHECK-NEXT: [[SWITCH_DOWNSHIFT:%.*]] = lshr i40 460303, [[SWITCH_SHIFTAMT]] ; CHECK-NEXT: [[SWITCH_MASKED:%.*]] = trunc i40 [[SWITCH_DOWNSHIFT]] to i8 ; CHECK-NEXT: ret i8 [[SWITCH_MASKED]] ; entry: %rem = urem i64 %x, 5 switch i64 %rem, label %default [ i64 0, label %sw.bb0 i64 1, label %sw.bb1 i64 2, label %sw.bb2 ] sw.bb0: ; preds = %entry br label %lor.end sw.bb1: ; preds = %entry br label %lor.end sw.bb2: ; preds = %entry br label %lor.end default: ; preds = %entry br label %lor.end lor.end: %0 = phi i8 [ 15, %sw.bb0 ], [ 6, %sw.bb1 ], [ 7, %sw.bb2 ], [ 0, %default ] ret i8 %0 } ; Negative test: Table size would not fit the register. define i8 @switch_lookup_with_small_i8_negative(i64 %x) { ; CHECK-LABEL: @switch_lookup_with_small_i8_negative( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[REM:%.*]] = urem i64 [[X:%.*]], 9 ; CHECK-NEXT: [[TMP0:%.*]] = icmp ult i64 [[REM]], 3 ; CHECK-NEXT: [[SWITCH_CAST:%.*]] = trunc i64 [[REM]] to i24 ; CHECK-NEXT: [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i24 [[SWITCH_CAST]], 8 ; CHECK-NEXT: [[SWITCH_DOWNSHIFT:%.*]] = lshr i24 460303, [[SWITCH_SHIFTAMT]] ; CHECK-NEXT: [[SWITCH_MASKED:%.*]] = trunc i24 [[SWITCH_DOWNSHIFT]] to i8 ; CHECK-NEXT: [[TMP1:%.*]] = select i1 [[TMP0]], i8 [[SWITCH_MASKED]], i8 0 ; CHECK-NEXT: ret i8 [[TMP1]] ; entry: %rem = urem i64 %x, 9 ; 9 * 8 = 72 > 64, not fit the register switch i64 %rem, label %default [ i64 0, label %sw.bb0 i64 1, label %sw.bb1 i64 2, label %sw.bb2 ] sw.bb0: ; preds = %entry br label %lor.end sw.bb1: ; preds = %entry br label %lor.end sw.bb2: ; preds = %entry br label %lor.end default: ; preds = %entry br label %lor.end lor.end: %0 = phi i8 [ 15, %sw.bb0 ], [ 6, %sw.bb1 ], [ 7, %sw.bb2 ], [ 0, %default ] ret i8 %0 } ; Negative test: The default branch is unreachable, also it has no result. define i1 @switch_lookup_with_small_i1_default_unreachable(i32 %x) { ; CHECK-LABEL: @switch_lookup_with_small_i1_default_unreachable( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[AND:%.*]] = and i32 [[X:%.*]], 15 ; CHECK-NEXT: ret i1 false ; entry: %and = and i32 %x, 15 switch i32 %and, label %default [ i32 4, label %phi.end i32 2, label %phi.end i32 10, label %phi.end i32 9, label %phi.end i32 1, label %sw.bb1.i i32 3, label %sw.bb1.i i32 5, label %sw.bb1.i i32 0, label %sw.bb1.i i32 6, label %sw.bb1.i i32 7, label %sw.bb1.i i32 8, label %sw.bb1.i ] sw.bb1.i: ; preds = %entry, %entry, %entry, %entry, %entry, %entry, %entry br label %phi.end default: ; preds = %entry unreachable phi.end: ; preds = %sw.bb1.i, %entry, %entry, %entry, %entry %retval = phi i1 [ false, %sw.bb1.i ], [ false, %entry ], [ false, %entry ], [ false, %entry ], [ false, %entry ] ret i1 %retval } ; Negative test: The result in default reachable, but its value is not const. define i1 @switch_lookup_with_small_i1_default_nonconst(i64 %x) { ; CHECK-LABEL: @switch_lookup_with_small_i1_default_nonconst( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[AND:%.*]] = and i64 [[X:%.*]], 15 ; CHECK-NEXT: switch i64 [[AND]], label [[DEFAULT:%.*]] [ ; CHECK-NEXT: i64 10, label [[LOR_END:%.*]] ; CHECK-NEXT: i64 1, label [[LOR_END]] ; CHECK-NEXT: i64 2, label [[LOR_END]] ; CHECK-NEXT: ] ; CHECK: default: ; CHECK-NEXT: [[CALL:%.*]] = tail call i1 @foo() ; CHECK-NEXT: br label [[LOR_END]] ; CHECK: lor.end: ; CHECK-NEXT: [[TMP0:%.*]] = phi i1 [ true, [[ENTRY:%.*]] ], [ [[CALL]], [[DEFAULT]] ], [ true, [[ENTRY]] ], [ true, [[ENTRY]] ] ; CHECK-NEXT: ret i1 [[TMP0]] ; entry: %and = and i64 %x, 15 switch i64 %and, label %default [ i64 10, label %lor.end i64 1, label %lor.end i64 2, label %lor.end ] default: ; preds = %entry %call = tail call i1 @foo() br label %lor.end lor.end: ; preds = %entry, %entry, %entry, %default %0 = phi i1 [ true, %entry ], [ %call, %default ], [ true, %entry ], [ true, %entry ] ret i1 %0 } ; Negative test: The upper bound index of switch is swapped. define void @switch_lookup_with_nonconst_range(i32 %x, i1 %cond) { ; CHECK-LABEL: @switch_lookup_with_nonconst_range( ; CHECK-NEXT: entry: ; CHECK-NEXT: br label [[FOR_PREHEADER:%.*]] ; CHECK: for.preheader: ; CHECK-NEXT: [[ADD:%.*]] = add nuw i32 [[X:%.*]], 1 ; CHECK-NEXT: br i1 [[COND:%.*]], label [[FOR_PREHEADER]], label [[FOR_END:%.*]] ; CHECK: for.end: ; CHECK-NEXT: [[TMP0:%.*]] = icmp ult i32 [[ADD]], 6 ; CHECK-NEXT: br i1 [[TMP0]], label [[SWITCH_LOOKUP:%.*]], label [[LOR_END:%.*]] ; CHECK: switch.lookup: ; CHECK-NEXT: [[SWITCH_GEP:%.*]] = getelementptr inbounds [6 x i32], ptr @switch.table.switch_lookup_with_nonconst_range, i32 0, i32 [[ADD]] ; CHECK-NEXT: [[SWITCH_LOAD:%.*]] = load i32, ptr [[SWITCH_GEP]], align 4 ; CHECK-NEXT: br label [[LOR_END]] ; CHECK: lor.end: ; CHECK-NEXT: [[RETVAL_0_I_I:%.*]] = phi i32 [ [[SWITCH_LOAD]], [[SWITCH_LOOKUP]] ], [ 1, [[FOR_END]] ] ; CHECK-NEXT: ret void ; entry: br label %for.preheader for.preheader: ; preds = %for.preheader, %entry %add = add nuw i32 %x, 1 ; the UpperBound is unconfirmed br i1 %cond, label %for.preheader, label %for.end for.end: ; preds = %for.preheader switch i32 %add, label %default [ i32 0, label %lor.end i32 1, label %lor.end i32 5, label %lor.end ] default: ; preds = %for.end br label %lor.end lor.end: ; preds = %default, %for.end, %for.end, %for.end %retval.0.i.i = phi i32 [ 1, %default ], [ 0, %for.end ], [ 0, %for.end ], [ 0, %for.end ] ret void }