; RUN: opt < %s -sccp -S | FileCheck %s ; This is a basic sanity check for constant propagation. The add instruction ; should be eliminated. define i32 @test1(i1 %B) { br i1 %B, label %BB1, label %BB2 BB1: ; preds = %0 %Val = add i32 0, 0 ; <i32> [#uses=1] br label %BB3 BB2: ; preds = %0 br label %BB3 BB3: ; preds = %BB2, %BB1 %Ret = phi i32 [ %Val, %BB1 ], [ 1, %BB2 ] ; <i32> [#uses=1] ret i32 %Ret ; CHECK: @test1 ; CHECK: %Ret = phi i32 [ 0, %BB1 ], [ 1, %BB2 ] } ; 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: @test2 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 ; CHECK: BB3: ; CHECK-NEXT: br i1 true, label %BB5, label %BB6 BB4: ret i32 %j2 ; CHECK: BB4: ; CHECK-NEXT: ret i32 1 BB5: %k3 = add i32 %k2, 1 br label %BB7 BB6: %k5 = add i32 %k2, 1 br label %BB7 ; CHECK: BB6: ; CHECK-NEXT: br label %BB7 BB7: %j4 = phi i32 [ 1, %BB5 ], [ %k2, %BB6 ] %k4 = phi i32 [ %k3, %BB5 ], [ %k5, %BB6 ] br label %BB2 ; CHECK: BB7: ; CHECK-NEXT: %k4 = phi i32 [ %k3, %BB5 ], [ undef, %BB6 ] ; CHECK-NEXT: br label %BB2 }