; RUN: llc < %s -O3 -march=thumb -mcpu=cortex-a9 | FileCheck %s -check-prefix=A9 ; @simple is the most basic chain of address induction variables. Chaining ; saves at least one register and avoids complex addressing and setup ; code. ; ; A9: @simple ; no expensive address computation in the preheader ; A9: lsl ; A9-NOT: lsl ; A9: %loop ; no complex address modes ; A9-NOT: lsl define i32 @simple(i32* %a, i32* %b, i32 %x) nounwind { entry: br label %loop loop: %iv = phi i32* [ %a, %entry ], [ %iv4, %loop ] %s = phi i32 [ 0, %entry ], [ %s4, %loop ] %v = load i32* %iv %iv1 = getelementptr inbounds i32* %iv, i32 %x %v1 = load i32* %iv1 %iv2 = getelementptr inbounds i32* %iv1, i32 %x %v2 = load i32* %iv2 %iv3 = getelementptr inbounds i32* %iv2, i32 %x %v3 = load i32* %iv3 %s1 = add i32 %s, %v %s2 = add i32 %s1, %v1 %s3 = add i32 %s2, %v2 %s4 = add i32 %s3, %v3 %iv4 = getelementptr inbounds i32* %iv3, i32 %x %cmp = icmp eq i32* %iv4, %b br i1 %cmp, label %exit, label %loop exit: ret i32 %s4 } ; @user is not currently chained because the IV is live across memory ops. ; ; A9: @user ; stride multiples computed in the preheader ; A9: lsl ; A9: lsl ; A9: %loop ; complex address modes ; A9: lsl ; A9: lsl define i32 @user(i32* %a, i32* %b, i32 %x) nounwind { entry: br label %loop loop: %iv = phi i32* [ %a, %entry ], [ %iv4, %loop ] %s = phi i32 [ 0, %entry ], [ %s4, %loop ] %v = load i32* %iv %iv1 = getelementptr inbounds i32* %iv, i32 %x %v1 = load i32* %iv1 %iv2 = getelementptr inbounds i32* %iv1, i32 %x %v2 = load i32* %iv2 %iv3 = getelementptr inbounds i32* %iv2, i32 %x %v3 = load i32* %iv3 %s1 = add i32 %s, %v %s2 = add i32 %s1, %v1 %s3 = add i32 %s2, %v2 %s4 = add i32 %s3, %v3 %iv4 = getelementptr inbounds i32* %iv3, i32 %x store i32 %s4, i32* %iv %cmp = icmp eq i32* %iv4, %b br i1 %cmp, label %exit, label %loop exit: ret i32 %s4 } ; @extrastride is a slightly more interesting case of a single ; complete chain with multiple strides. The test case IR is what LSR ; used to do, and exactly what we don't want to do. LSR's new IV ; chaining feature should now undo the damage. ; ; A9: extrastride: ; no spills ; A9-NOT: str ; only one stride multiple in the preheader ; A9: lsl ; A9-NOT: {{str r|lsl}} ; A9: %for.body{{$}} ; no complex address modes or reloads ; A9-NOT: {{ldr .*[sp]|lsl}} define void @extrastride(i8* nocapture %main, i32 %main_stride, i32* nocapture %res, i32 %x, i32 %y, i32 %z) nounwind { entry: %cmp8 = icmp eq i32 %z, 0 br i1 %cmp8, label %for.end, label %for.body.lr.ph for.body.lr.ph: ; preds = %entry %add.ptr.sum = shl i32 %main_stride, 1 ; s*2 %add.ptr1.sum = add i32 %add.ptr.sum, %main_stride ; s*3 %add.ptr2.sum = add i32 %x, %main_stride ; s + x %add.ptr4.sum = shl i32 %main_stride, 2 ; s*4 %add.ptr3.sum = add i32 %add.ptr2.sum, %add.ptr4.sum ; total IV stride = s*5+x br label %for.body for.body: ; preds = %for.body.lr.ph, %for.body %main.addr.011 = phi i8* [ %main, %for.body.lr.ph ], [ %add.ptr6, %for.body ] %i.010 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ] %res.addr.09 = phi i32* [ %res, %for.body.lr.ph ], [ %add.ptr7, %for.body ] %0 = bitcast i8* %main.addr.011 to i32* %1 = load i32* %0, align 4 %add.ptr = getelementptr inbounds i8* %main.addr.011, i32 %main_stride %2 = bitcast i8* %add.ptr to i32* %3 = load i32* %2, align 4 %add.ptr1 = getelementptr inbounds i8* %main.addr.011, i32 %add.ptr.sum %4 = bitcast i8* %add.ptr1 to i32* %5 = load i32* %4, align 4 %add.ptr2 = getelementptr inbounds i8* %main.addr.011, i32 %add.ptr1.sum %6 = bitcast i8* %add.ptr2 to i32* %7 = load i32* %6, align 4 %add.ptr3 = getelementptr inbounds i8* %main.addr.011, i32 %add.ptr4.sum %8 = bitcast i8* %add.ptr3 to i32* %9 = load i32* %8, align 4 %add = add i32 %3, %1 %add4 = add i32 %add, %5 %add5 = add i32 %add4, %7 %add6 = add i32 %add5, %9 store i32 %add6, i32* %res.addr.09, align 4 %add.ptr6 = getelementptr inbounds i8* %main.addr.011, i32 %add.ptr3.sum %add.ptr7 = getelementptr inbounds i32* %res.addr.09, i32 %y %inc = add i32 %i.010, 1 %cmp = icmp eq i32 %inc, %z br i1 %cmp, label %for.end, label %for.body for.end: ; preds = %for.body, %entry ret void } ; @foldedidx is an unrolled variant of this loop: ; for (unsigned long i = 0; i < len; i += s) { ; c[i] = a[i] + b[i]; ; } ; where 's' can be folded into the addressing mode. ; Consequently, we should *not* form any chains. ; ; A9: foldedidx: ; A9: ldrb{{(.w)?}} {{r[0-9]|lr}}, [{{r[0-9]|lr}}, #3] define void @foldedidx(i8* nocapture %a, i8* nocapture %b, i8* nocapture %c) nounwind ssp { entry: br label %for.body for.body: ; preds = %for.body, %entry %i.07 = phi i32 [ 0, %entry ], [ %inc.3, %for.body ] %arrayidx = getelementptr inbounds i8* %a, i32 %i.07 %0 = load i8* %arrayidx, align 1 %conv5 = zext i8 %0 to i32 %arrayidx1 = getelementptr inbounds i8* %b, i32 %i.07 %1 = load i8* %arrayidx1, align 1 %conv26 = zext i8 %1 to i32 %add = add nsw i32 %conv26, %conv5 %conv3 = trunc i32 %add to i8 %arrayidx4 = getelementptr inbounds i8* %c, i32 %i.07 store i8 %conv3, i8* %arrayidx4, align 1 %inc1 = or i32 %i.07, 1 %arrayidx.1 = getelementptr inbounds i8* %a, i32 %inc1 %2 = load i8* %arrayidx.1, align 1 %conv5.1 = zext i8 %2 to i32 %arrayidx1.1 = getelementptr inbounds i8* %b, i32 %inc1 %3 = load i8* %arrayidx1.1, align 1 %conv26.1 = zext i8 %3 to i32 %add.1 = add nsw i32 %conv26.1, %conv5.1 %conv3.1 = trunc i32 %add.1 to i8 %arrayidx4.1 = getelementptr inbounds i8* %c, i32 %inc1 store i8 %conv3.1, i8* %arrayidx4.1, align 1 %inc.12 = or i32 %i.07, 2 %arrayidx.2 = getelementptr inbounds i8* %a, i32 %inc.12 %4 = load i8* %arrayidx.2, align 1 %conv5.2 = zext i8 %4 to i32 %arrayidx1.2 = getelementptr inbounds i8* %b, i32 %inc.12 %5 = load i8* %arrayidx1.2, align 1 %conv26.2 = zext i8 %5 to i32 %add.2 = add nsw i32 %conv26.2, %conv5.2 %conv3.2 = trunc i32 %add.2 to i8 %arrayidx4.2 = getelementptr inbounds i8* %c, i32 %inc.12 store i8 %conv3.2, i8* %arrayidx4.2, align 1 %inc.23 = or i32 %i.07, 3 %arrayidx.3 = getelementptr inbounds i8* %a, i32 %inc.23 %6 = load i8* %arrayidx.3, align 1 %conv5.3 = zext i8 %6 to i32 %arrayidx1.3 = getelementptr inbounds i8* %b, i32 %inc.23 %7 = load i8* %arrayidx1.3, align 1 %conv26.3 = zext i8 %7 to i32 %add.3 = add nsw i32 %conv26.3, %conv5.3 %conv3.3 = trunc i32 %add.3 to i8 %arrayidx4.3 = getelementptr inbounds i8* %c, i32 %inc.23 store i8 %conv3.3, i8* %arrayidx4.3, align 1 %inc.3 = add nsw i32 %i.07, 4 %exitcond.3 = icmp eq i32 %inc.3, 400 br i1 %exitcond.3, label %for.end, label %for.body for.end: ; preds = %for.body ret void } ; @testNeon is an important example of the nead for ivchains. ; ; Currently we have three extra add.w's that keep the store address ; live past the next increment because ISEL is unfortunately undoing ; the store chain. ISEL also fails to convert the stores to ; post-increment addressing. However, the loads should use ; post-increment addressing, no add's or add.w's beyond the three ; mentioned. Most importantly, there should be no spills or reloads! ; ; A9: testNeon: ; A9: %.lr.ph ; A9-NOT: lsl.w ; A9-NOT: {{ldr|str|adds|add r}} ; A9: add.w r ; A9-NOT: {{ldr|str|adds|add r}} ; A9: add.w r ; A9-NOT: {{ldr|str|adds|add r}} ; A9: add.w r ; A9-NOT: {{ldr|str|adds|add r}} ; A9-NOT: add.w r ; A9: bne define hidden void @testNeon(i8* %ref_data, i32 %ref_stride, i32 %limit, <16 x i8>* nocapture %data) nounwind optsize { %1 = icmp sgt i32 %limit, 0 br i1 %1, label %.lr.ph, label %45 .lr.ph: ; preds = %0 %2 = shl nsw i32 %ref_stride, 1 %3 = mul nsw i32 %ref_stride, 3 %4 = shl nsw i32 %ref_stride, 2 %5 = mul nsw i32 %ref_stride, 5 %6 = mul nsw i32 %ref_stride, 6 %7 = mul nsw i32 %ref_stride, 7 %8 = shl nsw i32 %ref_stride, 3 %9 = sub i32 0, %8 %10 = mul i32 %limit, -64 br label %11 ;