; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=sccp -S | FileCheck %s ; This is a basic correctness check for constant propagation. The add ; instruction should be eliminated. define i32 @test1(i1 %B) { ; CHECK-LABEL: @test1( ; CHECK-NEXT: br i1 [[B:%.*]], label [[BB1:%.*]], label [[BB2:%.*]] ; CHECK: BB1: ; CHECK-NEXT: br label [[BB3:%.*]] ; CHECK: BB2: ; CHECK-NEXT: br label [[BB3]] ; CHECK: BB3: ; CHECK-NEXT: [[RET:%.*]] = phi i32 [ 0, [[BB1]] ], [ 1, [[BB2]] ] ; CHECK-NEXT: ret i32 [[RET]] ; br i1 %B, label %BB1, label %BB2 BB1: ; preds = %0 %Val = add i32 0, 0 ; [#uses=1] br label %BB3 BB2: ; preds = %0 br label %BB3 BB3: ; preds = %BB2, %BB1 %Ret = phi i32 [ %Val, %BB1 ], [ 1, %BB2 ] ; [#uses=1] ret i32 %Ret } ; This is the test case taken from appel's book that illustrates a hard case ; that SCCP gets right. ; define i32 @test2(i32 %i0, i32 %j0) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: BB1: ; CHECK-NEXT: br label [[BB2:%.*]] ; CHECK: BB2: ; CHECK-NEXT: [[K2:%.*]] = phi i32 [ [[K3:%.*]], [[BB7:%.*]] ], [ 0, [[BB1:%.*]] ] ; CHECK-NEXT: [[KCOND:%.*]] = icmp slt i32 [[K2]], 100 ; CHECK-NEXT: br i1 [[KCOND]], label [[BB3:%.*]], label [[BB4:%.*]] ; CHECK: BB3: ; CHECK-NEXT: br label [[BB5:%.*]] ; CHECK: BB4: ; CHECK-NEXT: ret i32 1 ; CHECK: BB5: ; CHECK-NEXT: [[K3]] = add i32 [[K2]], 1 ; CHECK-NEXT: br label [[BB7]] ; CHECK: BB7: ; CHECK-NEXT: br label [[BB2]] ; BB1: br label %BB2 BB2: %j2 = phi i32 [ %j4, %BB7 ], [ 1, %BB1 ] %k2 = phi i32 [ %k4, %BB7 ], [ 0, %BB1 ] %kcond = icmp slt i32 %k2, 100 br i1 %kcond, label %BB3, label %BB4 BB3: %jcond = icmp slt i32 %j2, 20 br i1 %jcond, label %BB5, label %BB6 BB4: ret i32 %j2 BB5: %k3 = add i32 %k2, 1 br label %BB7 BB6: %k5 = add i32 %k2, 1 br label %BB7 BB7: %j4 = phi i32 [ 1, %BB5 ], [ %k2, %BB6 ] %k4 = phi i32 [ %k3, %BB5 ], [ %k5, %BB6 ] br label %BB2 }