; RUN: opt < %s -licm -S | FileCheck %s ; RUN: opt < %s -aa-pipeline=basic-aa -passes='require,loop(licm)' -S | FileCheck %s ; RUN: opt < %s -licm -enable-mssa-loop-dependency=true -verify-memoryssa -S | FileCheck %s @X = global i32 0 ; [#uses=1] declare void @foo() declare i32 @llvm.bitreverse.i32(i32) ; This testcase tests for a problem where LICM hoists ; potentially trapping instructions when they are not guaranteed to execute. define i32 @test1(i1 %c) { ; CHECK-LABEL: @test1( %A = load i32, i32* @X ; [#uses=2] br label %Loop Loop: ; preds = %LoopTail, %0 call void @foo( ) br i1 %c, label %LoopTail, label %IfUnEqual IfUnEqual: ; preds = %Loop ; CHECK: IfUnEqual: ; CHECK-NEXT: sdiv i32 4, %A %B1 = sdiv i32 4, %A ; [#uses=1] br label %LoopTail LoopTail: ; preds = %IfUnEqual, %Loop %B = phi i32 [ 0, %Loop ], [ %B1, %IfUnEqual ] ; [#uses=1] br i1 %c, label %Loop, label %Out Out: ; preds = %LoopTail %C = sub i32 %A, %B ; [#uses=1] ret i32 %C } declare void @foo2(i32) nounwind ;; It is ok and desirable to hoist this potentially trapping instruction. define i32 @test2(i1 %c) { ; CHECK-LABEL: @test2( ; CHECK-NEXT: load i32, i32* @X ; CHECK-NEXT: %B = sdiv i32 4, %A %A = load i32, i32* @X br label %Loop Loop: ;; Should have hoisted this div! %B = sdiv i32 4, %A br label %loop2 loop2: call void @foo2( i32 %B ) br i1 %c, label %Loop, label %Out Out: %C = sub i32 %A, %B ret i32 %C } ; This loop invariant instruction should be constant folded, not hoisted. define i32 @test3(i1 %c) { ; CHECK-LABEL: define i32 @test3( ; CHECK: call void @foo2(i32 6) %A = load i32, i32* @X ; [#uses=2] br label %Loop Loop: %B = add i32 4, 2 ; [#uses=2] call void @foo2( i32 %B ) br i1 %c, label %Loop, label %Out Out: ; preds = %Loop %C = sub i32 %A, %B ; [#uses=1] ret i32 %C } ; CHECK-LABEL: @test4( ; CHECK: call ; CHECK: sdiv ; CHECK: ret define i32 @test4(i32 %x, i32 %y) nounwind uwtable ssp { entry: br label %for.body for.body: ; preds = %entry, %for.body %i.02 = phi i32 [ 0, %entry ], [ %inc, %for.body ] %n.01 = phi i32 [ 0, %entry ], [ %add, %for.body ] call void @foo_may_call_exit(i32 0) %div = sdiv i32 %x, %y %add = add nsw i32 %n.01, %div %inc = add nsw i32 %i.02, 1 %cmp = icmp slt i32 %inc, 10000 br i1 %cmp, label %for.body, label %for.end for.end: ; preds = %for.body %n.0.lcssa = phi i32 [ %add, %for.body ] ret i32 %n.0.lcssa } declare void @foo_may_call_exit(i32) ; PR14854 ; CHECK-LABEL: @test5( ; CHECK: extractvalue ; CHECK: br label %tailrecurse ; CHECK: tailrecurse: ; CHECK: ifend: ; CHECK: insertvalue define { i32*, i32 } @test5(i32 %i, { i32*, i32 } %e) { entry: br label %tailrecurse tailrecurse: ; preds = %then, %entry %i.tr = phi i32 [ %i, %entry ], [ %cmp2, %then ] %out = extractvalue { i32*, i32 } %e, 1 %d = insertvalue { i32*, i32 } %e, i32* null, 0 %cmp1 = icmp sgt i32 %out, %i.tr br i1 %cmp1, label %then, label %ifend then: ; preds = %tailrecurse call void @foo() %cmp2 = add i32 %i.tr, 1 br label %tailrecurse ifend: ; preds = %tailrecurse ret { i32*, i32 } %d } ; CHECK: define void @test6(float %f) ; CHECK: fneg ; CHECK: br label %for.body define void @test6(float %f) #2 { entry: br label %for.body for.body: ; preds = %for.body, %entry %i = phi i32 [ 0, %entry ], [ %inc, %for.body ] call void @foo_may_call_exit(i32 0) %neg = fneg float %f call void @use(float %neg) %inc = add nsw i32 %i, 1 %cmp = icmp slt i32 %inc, 10000 br i1 %cmp, label %for.body, label %for.end for.end: ; preds = %for.body ret void } declare void @use(float) ; CHECK: define i32 @hoist_bitreverse(i32 %0) ; CHECK: bitreverse ; CHECK: br label %header define i32 @hoist_bitreverse(i32 %0) { br label %header header: %sum = phi i32 [ 0, %1 ], [ %5, %latch ] %2 = phi i32 [ 0, %1 ], [ %6, %latch ] %3 = icmp slt i32 %2, 1024 br i1 %3, label %body, label %return body: %4 = call i32 @llvm.bitreverse.i32(i32 %0) %5 = add i32 %sum, %4 br label %latch latch: %6 = add nsw i32 %2, 1 br label %header return: ret i32 %sum } ; Can neither sink nor hoist define i32 @test_volatile(i1 %c) { ; CHECK-LABEL: @test_volatile( ; CHECK-LABEL: Loop: ; CHECK: load volatile i32, i32* @X ; CHECK-LABEL: Out: br label %Loop Loop: %A = load volatile i32, i32* @X br i1 %c, label %Loop, label %Out Out: ret i32 %A } declare {}* @llvm.invariant.start.p0i8(i64, i8* nocapture) nounwind readonly declare void @llvm.invariant.end.p0i8({}*, i64, i8* nocapture) nounwind declare void @escaping.invariant.start({}*) nounwind ; invariant.start dominates the load, and in this scope, the ; load is invariant. So, we can hoist the `addrld` load out of the loop. define i32 @test_fence(i8* %addr, i32 %n, i8* %volatile) { ; CHECK-LABEL: @test_fence ; CHECK-LABEL: entry ; CHECK: invariant.start ; CHECK: %addrld = load atomic i32, i32* %addr.i unordered, align 8 ; CHECK: br label %loop entry: %gep = getelementptr inbounds i8, i8* %addr, i64 8 %addr.i = bitcast i8* %gep to i32 * store atomic i32 5, i32 * %addr.i unordered, align 8 fence release %invst = call {}* @llvm.invariant.start.p0i8(i64 4, i8* %gep) br label %loop loop: %indvar = phi i32 [ %indvar.next, %loop ], [ 0, %entry ] %sum = phi i32 [ %sum.next, %loop ], [ 0, %entry ] %volload = load atomic i8, i8* %volatile unordered, align 8 fence acquire %volchk = icmp eq i8 %volload, 0 %addrld = load atomic i32, i32* %addr.i unordered, align 8 %sel = select i1 %volchk, i32 0, i32 %addrld %sum.next = add i32 %sel, %sum %indvar.next = add i32 %indvar, 1 %cond = icmp slt i32 %indvar.next, %n br i1 %cond, label %loop, label %loopexit loopexit: ret i32 %sum } ; Same as test above, but the load is no longer invariant (presence of ; invariant.end). We cannot hoist the addrld out of loop. define i32 @test_fence1(i8* %addr, i32 %n, i8* %volatile) { ; CHECK-LABEL: @test_fence1 ; CHECK-LABEL: entry ; CHECK: invariant.start ; CHECK-NEXT: invariant.end ; CHECK-NEXT: br label %loop entry: %gep = getelementptr inbounds i8, i8* %addr, i64 8 %addr.i = bitcast i8* %gep to i32 * store atomic i32 5, i32 * %addr.i unordered, align 8 fence release %invst = call {}* @llvm.invariant.start.p0i8(i64 4, i8* %gep) call void @llvm.invariant.end.p0i8({}* %invst, i64 4, i8* %gep) br label %loop loop: %indvar = phi i32 [ %indvar.next, %loop ], [ 0, %entry ] %sum = phi i32 [ %sum.next, %loop ], [ 0, %entry ] %volload = load atomic i8, i8* %volatile unordered, align 8 fence acquire %volchk = icmp eq i8 %volload, 0 %addrld = load atomic i32, i32* %addr.i unordered, align 8 %sel = select i1 %volchk, i32 0, i32 %addrld %sum.next = add i32 %sel, %sum %indvar.next = add i32 %indvar, 1 %cond = icmp slt i32 %indvar.next, %n br i1 %cond, label %loop, label %loopexit loopexit: ret i32 %sum } ; same as test above, but instead of invariant.end, we have the result of ; invariant.start escaping through a call. We cannot hoist the load. define i32 @test_fence2(i8* %addr, i32 %n, i8* %volatile) { ; CHECK-LABEL: @test_fence2 ; CHECK-LABEL: entry ; CHECK-NOT: load ; CHECK: br label %loop entry: %gep = getelementptr inbounds i8, i8* %addr, i64 8 %addr.i = bitcast i8* %gep to i32 * store atomic i32 5, i32 * %addr.i unordered, align 8 fence release %invst = call {}* @llvm.invariant.start.p0i8(i64 4, i8* %gep) call void @escaping.invariant.start({}* %invst) br label %loop loop: %indvar = phi i32 [ %indvar.next, %loop ], [ 0, %entry ] %sum = phi i32 [ %sum.next, %loop ], [ 0, %entry ] %volload = load atomic i8, i8* %volatile unordered, align 8 fence acquire %volchk = icmp eq i8 %volload, 0 %addrld = load atomic i32, i32* %addr.i unordered, align 8 %sel = select i1 %volchk, i32 0, i32 %addrld %sum.next = add i32 %sel, %sum %indvar.next = add i32 %indvar, 1 %cond = icmp slt i32 %indvar.next, %n br i1 %cond, label %loop, label %loopexit loopexit: ret i32 %sum } ; FIXME: invariant.start dominates the load, and in this scope, the ; load is invariant. So, we can hoist the `addrld` load out of the loop. ; Consider the loadoperand addr.i bitcasted before being passed to ; invariant.start define i32 @test_fence3(i32* %addr, i32 %n, i8* %volatile) { ; CHECK-LABEL: @test_fence3 ; CHECK-LABEL: entry ; CHECK: invariant.start ; CHECK-NOT: %addrld = load atomic i32, i32* %addr.i unordered, align 8 ; CHECK: br label %loop entry: %addr.i = getelementptr inbounds i32, i32* %addr, i64 8 %gep = bitcast i32* %addr.i to i8 * store atomic i32 5, i32 * %addr.i unordered, align 8 fence release %invst = call {}* @llvm.invariant.start.p0i8(i64 4, i8* %gep) br label %loop loop: %indvar = phi i32 [ %indvar.next, %loop ], [ 0, %entry ] %sum = phi i32 [ %sum.next, %loop ], [ 0, %entry ] %volload = load atomic i8, i8* %volatile unordered, align 8 fence acquire %volchk = icmp eq i8 %volload, 0 %addrld = load atomic i32, i32* %addr.i unordered, align 8 %sel = select i1 %volchk, i32 0, i32 %addrld %sum.next = add i32 %sel, %sum %indvar.next = add i32 %indvar, 1 %cond = icmp slt i32 %indvar.next, %n br i1 %cond, label %loop, label %loopexit loopexit: ret i32 %sum } ; We should not hoist the addrld out of the loop. define i32 @test_fence4(i32* %addr, i32 %n, i8* %volatile) { ; CHECK-LABEL: @test_fence4 ; CHECK-LABEL: entry ; CHECK-NOT: %addrld = load atomic i32, i32* %addr.i unordered, align 8 ; CHECK: br label %loop entry: %addr.i = getelementptr inbounds i32, i32* %addr, i64 8 %gep = bitcast i32* %addr.i to i8 * br label %loop loop: %indvar = phi i32 [ %indvar.next, %loop ], [ 0, %entry ] %sum = phi i32 [ %sum.next, %loop ], [ 0, %entry ] store atomic i32 5, i32 * %addr.i unordered, align 8 fence release %invst = call {}* @llvm.invariant.start.p0i8(i64 4, i8* %gep) %volload = load atomic i8, i8* %volatile unordered, align 8 fence acquire %volchk = icmp eq i8 %volload, 0 %addrld = load atomic i32, i32* %addr.i unordered, align 8 %sel = select i1 %volchk, i32 0, i32 %addrld %sum.next = add i32 %sel, %sum %indvar.next = add i32 %indvar, 1 %cond = icmp slt i32 %indvar.next, %n br i1 %cond, label %loop, label %loopexit loopexit: ret i32 %sum } ; We can't hoist the invariant load out of the loop because ; the marker is given a variable size (-1). define i32 @test_fence5(i8* %addr, i32 %n, i8* %volatile) { ; CHECK-LABEL: @test_fence5 ; CHECK-LABEL: entry ; CHECK: invariant.start ; CHECK-NOT: %addrld = load atomic i32, i32* %addr.i unordered, align 8 ; CHECK: br label %loop entry: %gep = getelementptr inbounds i8, i8* %addr, i64 8 %addr.i = bitcast i8* %gep to i32 * store atomic i32 5, i32 * %addr.i unordered, align 8 fence release %invst = call {}* @llvm.invariant.start.p0i8(i64 -1, i8* %gep) br label %loop loop: %indvar = phi i32 [ %indvar.next, %loop ], [ 0, %entry ] %sum = phi i32 [ %sum.next, %loop ], [ 0, %entry ] %volload = load atomic i8, i8* %volatile unordered, align 8 fence acquire %volchk = icmp eq i8 %volload, 0 %addrld = load atomic i32, i32* %addr.i unordered, align 8 %sel = select i1 %volchk, i32 0, i32 %addrld %sum.next = add i32 %sel, %sum %indvar.next = add i32 %indvar, 1 %cond = icmp slt i32 %indvar.next, %n br i1 %cond, label %loop, label %loopexit loopexit: ret i32 %sum }