; RUN: llc -march=hexagon < %s | FileCheck %s ; DAG combiner folds sequences of shifts, which can sometimes obscure ; optimization opportunities. For example ; ; unsigned int c(unsigned int b, unsigned int *a) { ; unsigned int bitidx = b >> 5; ; return a[bitidx]; ; } ; ; produces ; (add x (shl (srl y 5) 2)) ; which is then folded into ; (add x (and (srl y 3) 1FFFFFFC)) ; ; That results in a constant-extended and: ; r0 = and(##536870908,lsr(r0,#3)) ; r0 = memw(r1+r0<<#0) ; whereas ; r0 = lsr(r0,#5) ; r0 = memw(r1+r0<<#2) ; is more desirable. target triple = "hexagon" ; CHECK-LABEL: load_0 ; CHECK: memw(r{{[0-9]+}}+r{{[0-9]}}<<#2) define i32 @load_0(i32 %b, i32* nocapture readonly %a) #0 { entry: %shr = lshr i32 %b, 5 %arrayidx = getelementptr inbounds i32, i32* %a, i32 %shr %0 = load i32, i32* %arrayidx, align 4 ret i32 %0 } ; This would require r0<<#3, which is not legal. ; CHECK-LABEL: load_1 ; CHECK: memw(r{{[0-9]+}}+r{{[0-9]}}<<#0) define i32 @load_1(i32 %b, [3 x i32]* nocapture readonly %a) #0 { entry: %shr = lshr i32 %b, 5 %arrayidx = getelementptr inbounds [3 x i32], [3 x i32]* %a, i32 %shr, i32 0 %0 = load i32, i32* %arrayidx, align 4 ret i32 %0 } ; CHECK-LABEL: store_0 ; CHECK: memw(r{{[0-9]+}}+r{{[0-9]}}<<#2) define void @store_0(i32 %b, i32* nocapture %a, i32 %v) #1 { entry: %shr = lshr i32 %b, 5 %arrayidx = getelementptr inbounds i32, i32* %a, i32 %shr store i32 %v, i32* %arrayidx, align 4 ret void } attributes #0 = { norecurse nounwind readonly "target-cpu"="hexagonv60" "target-features"="-hvx,-long-calls" } attributes #1 = { norecurse nounwind "target-cpu"="hexagonv60" "target-features"="-hvx,-long-calls" }