const Loop *L,
ScalarEvolution &SE, DominatorTree &DT) {
if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Reg)) {
- // If this is an addrec for another loop, it should be an invariant
- // with respect to L since L is the innermost loop (at least
- // for now LSR only handles innermost loops).
+ // If this is an addrec for another loop, don't second-guess its addrec phi
+ // nodes. LSR isn't currently smart enough to reason about more than one
+ // loop at a time. LSR has already run on inner loops, will not run on outer
+ // loops, and cannot be expected to change sibling loops.
if (AR->getLoop() != L) {
// If the AddRec exists, consider it's register free and leave it alone.
if (isExistingPhi(AR, SE))
return;
- // Otherwise, it will be an invariant with respect to Loop L.
- ++NumRegs;
+ // Otherwise, do not consider this formula at all.
+ Lose();
return;
}
AddRecCost += 1; /// TODO: This should be a function of the stride.
+++ /dev/null
-; RUN: opt -loop-reduce -S < %s | FileCheck %s
-; Check when we use an outerloop induction variable inside of an innerloop
-; induction value expr, LSR can still choose to use single induction variable
-; for the innerloop and share it in multiple induction value exprs.
-
-target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-unknown-linux-gnu"
-
-define void @foo(i32 %size, i32 %nsteps, i32 %hsize, i32* %lined, i8* %maxarray) {
-entry:
- %cmp215 = icmp sgt i32 %size, 1
- %t0 = zext i32 %size to i64
- %t1 = sext i32 %nsteps to i64
- %sub2 = sub i64 %t0, 2
- br label %for.body
-
-for.body: ; preds = %for.inc, %entry
- %indvars.iv2 = phi i64 [ %indvars.iv.next3, %for.inc ], [ 0, %entry ]
- %t2 = mul nsw i64 %indvars.iv2, %t0
- br i1 %cmp215, label %for.body2.preheader, label %for.inc
-
-for.body2.preheader: ; preds = %for.body
- br label %for.body2
-
-; Check LSR only generates one induction variable for for.body2 and the induction
-; variable will be shared by multiple array accesses.
-; CHECK: for.body2:
-; CHECK-NEXT: [[LSR:%[^,]+]] = phi i64 [ %lsr.iv.next, %for.body2 ], [ 0, %for.body2.preheader ]
-; CHECK-NOT: = phi i64 [ {{.*}}, %for.body2 ], [ {{.*}}, %for.body2.preheader ]
-; CHECK: [[SCEVGEP1:%[^,]+]] = getelementptr i8, i8* %maxarray, i64 [[LSR]]
-; CHECK: [[SCEVGEP2:%[^,]+]] = getelementptr i8, i8* [[SCEVGEP1]], i64 1
-; CHECK: {{.*}} = load i8, i8* [[SCEVGEP2]], align 1
-; CHECK: [[SCEVGEP3:%[^,]+]] = getelementptr i8, i8* {{.*}}, i64 [[LSR]]
-; CHECK: {{.*}} = load i8, i8* [[SCEVGEP3]], align 1
-; CHECK: [[SCEVGEP4:%[^,]+]] = getelementptr i8, i8* {{.*}}, i64 [[LSR]]
-; CHECK: store i8 {{.*}}, i8* [[SCEVGEP4]], align 1
-; CHECK: br i1 %exitcond, label %for.body2, label %for.inc.loopexit
-
-for.body2: ; preds = %for.body2.preheader, %for.body2
- %indvars.iv = phi i64 [ 1, %for.body2.preheader ], [ %indvars.iv.next, %for.body2 ]
- %arrayidx1 = getelementptr inbounds i8, i8* %maxarray, i64 %indvars.iv
- %v1 = load i8, i8* %arrayidx1, align 1
- %idx2 = add nsw i64 %indvars.iv, %sub2
- %arrayidx2 = getelementptr inbounds i8, i8* %maxarray, i64 %idx2
- %v2 = load i8, i8* %arrayidx2, align 1
- %tmpv = xor i8 %v1, %v2
- %t4 = add nsw i64 %t2, %indvars.iv
- %add.ptr = getelementptr inbounds i8, i8* %maxarray, i64 %t4
- store i8 %tmpv, i8* %add.ptr, align 1
- %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
- %wide.trip.count = zext i32 %size to i64
- %exitcond = icmp ne i64 %indvars.iv.next, %wide.trip.count
- br i1 %exitcond, label %for.body2, label %for.inc.loopexit
-
-for.inc.loopexit: ; preds = %for.body2
- br label %for.inc
-
-for.inc: ; preds = %for.inc.loopexit, %for.body
- %indvars.iv.next3 = add nuw nsw i64 %indvars.iv2, 1
- %cmp = icmp slt i64 %indvars.iv.next3, %t1
- br i1 %cmp, label %for.body, label %for.end.loopexit
-
-for.end.loopexit: ; preds = %for.inc
- ret void
-}