; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=indvars -S | FileCheck %s declare i1 @cond() declare i32 @llvm.smax.i32(i32, i32) ; FIXME: In all tests in this file, signed_cond is equivalent to unsigned_cond, and therefore ; one of the checks in the inner loop can be removed. The key to proving it is to prove that ; %iv starts from something that is non-negative and only goes up. The positivity of its start ; follows from the fact that %outer.iv also starts from somethign non-negative and only goes ; up or remains same between iterations. define i32 @test_01(i32 %a, i32 %b) { ; CHECK-LABEL: @test_01( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[B_IS_NON_NEGATIVE:%.*]] = icmp sge i32 [[B:%.*]], 0 ; CHECK-NEXT: br i1 [[B_IS_NON_NEGATIVE]], label [[OUTER_PREHEADER:%.*]], label [[FAILURE:%.*]] ; CHECK: outer.preheader: ; CHECK-NEXT: br label [[OUTER:%.*]] ; CHECK: outer: ; CHECK-NEXT: [[OUTER_IV:%.*]] = phi i32 [ [[IV_NEXT_LCSSA:%.*]], [[OUTER_BACKEDGE:%.*]] ], [ 0, [[OUTER_PREHEADER]] ] ; CHECK-NEXT: br label [[INNER:%.*]] ; CHECK: inner: ; CHECK-NEXT: [[IV:%.*]] = phi i32 [ [[OUTER_IV]], [[OUTER]] ], [ [[IV_NEXT:%.*]], [[INNER_BACKEDGE:%.*]] ] ; CHECK-NEXT: [[SIGNED_COND:%.*]] = icmp slt i32 [[IV]], [[B]] ; CHECK-NEXT: br i1 [[SIGNED_COND]], label [[INNER_1:%.*]], label [[SIDE_EXIT:%.*]] ; CHECK: inner.1: ; CHECK-NEXT: [[UNSIGNED_COND:%.*]] = icmp ult i32 [[IV]], [[B]] ; CHECK-NEXT: br i1 [[UNSIGNED_COND]], label [[INNER_BACKEDGE]], label [[SIDE_EXIT]] ; CHECK: inner.backedge: ; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i32 [[IV]], 1 ; CHECK-NEXT: [[INNER_LOOP_COND:%.*]] = call i1 @cond() ; CHECK-NEXT: br i1 [[INNER_LOOP_COND]], label [[INNER]], label [[OUTER_BACKEDGE]] ; CHECK: outer.backedge: ; CHECK-NEXT: [[IV_NEXT_LCSSA]] = phi i32 [ [[IV_NEXT]], [[INNER_BACKEDGE]] ] ; CHECK-NEXT: [[OUTER_LOOP_COND:%.*]] = call i1 @cond() ; CHECK-NEXT: br i1 [[OUTER_LOOP_COND]], label [[OUTER]], label [[EXIT:%.*]] ; CHECK: failure: ; CHECK-NEXT: unreachable ; CHECK: side.exit: ; CHECK-NEXT: ret i32 0 ; CHECK: exit: ; CHECK-NEXT: ret i32 1 ; entry: %b_is_non_negative = icmp sge i32 %b, 0 br i1 %b_is_non_negative, label %outer, label %failure outer: %outer.iv = phi i32 [0, %entry], [%iv.next, %outer.backedge] br label %inner inner: %iv = phi i32 [%outer.iv, %outer], [%iv.next, %inner.backedge] %signed_cond = icmp slt i32 %iv, %b br i1 %signed_cond, label %inner.1, label %side.exit inner.1: %unsigned_cond = icmp ult i32 %iv, %b br i1 %unsigned_cond, label %inner.backedge, label %side.exit inner.backedge: %iv.next = add nuw nsw i32 %iv, 1 %inner.loop.cond = call i1 @cond() br i1 %inner.loop.cond, label %inner, label %outer.backedge outer.backedge: %outer.loop.cond = call i1 @cond() br i1 %outer.loop.cond, label %outer, label %exit failure: unreachable side.exit: ret i32 0 exit: ret i32 1 } ; FIXME: iv =s 0 --> iv iv