1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; RUN: opt < %s -passes=sccp -S | FileCheck %s 3 4; This is a basic correctness check for constant propagation. The add 5; instruction should be eliminated. 6 7define i32 @test1(i1 %B) { 8; CHECK-LABEL: @test1( 9; CHECK-NEXT: br i1 [[B:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] 10; CHECK: BB1: 11; CHECK-NEXT: br label [[BB3:%.*]] 12; CHECK: BB2: 13; CHECK-NEXT: br label [[BB3]] 14; CHECK: BB3: 15; CHECK-NEXT: [[RET:%.*]] = phi i32 [ 0, [[BB1]] ], [ 1, [[BB2]] ] 16; CHECK-NEXT: ret i32 [[RET]] 17; 18 br i1 %B, label %BB1, label %BB2 19BB1: ; preds = %0 20 %Val = add i32 0, 0 ; <i32> [#uses=1] 21 br label %BB3 22BB2: ; preds = %0 23 br label %BB3 24BB3: ; preds = %BB2, %BB1 25 %Ret = phi i32 [ %Val, %BB1 ], [ 1, %BB2 ] ; <i32> [#uses=1] 26 ret i32 %Ret 27 28} 29 30; This is the test case taken from appel's book that illustrates a hard case 31; that SCCP gets right. 32; 33define i32 @test2(i32 %i0, i32 %j0) { 34; CHECK-LABEL: @test2( 35; CHECK-NEXT: BB1: 36; CHECK-NEXT: br label [[BB2:%.*]] 37; CHECK: BB2: 38; CHECK-NEXT: [[K2:%.*]] = phi i32 [ [[K3:%.*]], [[BB7:%.*]] ], [ 0, [[BB1:%.*]] ] 39; CHECK-NEXT: [[KCOND:%.*]] = icmp slt i32 [[K2]], 100 40; CHECK-NEXT: br i1 [[KCOND]], label [[BB3:%.*]], label [[BB4:%.*]] 41; CHECK: BB3: 42; CHECK-NEXT: br label [[BB5:%.*]] 43; CHECK: BB4: 44; CHECK-NEXT: ret i32 1 45; CHECK: BB5: 46; CHECK-NEXT: [[K3]] = add i32 [[K2]], 1 47; CHECK-NEXT: br label [[BB7]] 48; CHECK: BB7: 49; CHECK-NEXT: br label [[BB2]] 50; 51BB1: 52 br label %BB2 53BB2: 54 %j2 = phi i32 [ %j4, %BB7 ], [ 1, %BB1 ] 55 %k2 = phi i32 [ %k4, %BB7 ], [ 0, %BB1 ] 56 %kcond = icmp slt i32 %k2, 100 57 br i1 %kcond, label %BB3, label %BB4 58BB3: 59 %jcond = icmp slt i32 %j2, 20 60 br i1 %jcond, label %BB5, label %BB6 61BB4: 62 ret i32 %j2 63BB5: 64 %k3 = add i32 %k2, 1 65 br label %BB7 66BB6: 67 %k5 = add i32 %k2, 1 68 br label %BB7 69BB7: 70 %j4 = phi i32 [ 1, %BB5 ], [ %k2, %BB6 ] 71 %k4 = phi i32 [ %k3, %BB5 ], [ %k5, %BB6 ] 72 br label %BB2 73} 74 75