Vigneshwar Jayakumar 469702c5d5
[LICM] Sink unused l-invariant loads in preheader. (#157559)
Unused loop invariant loads were not sunk from the preheader to the exit
block, increasing live range.

This commit moves the sinkUnusedInvariant logic from indvarsimplify to
LICM also adds functionality to sink unused load that's not
clobbered by the loop body.
2025-10-30 09:23:04 -05:00

85 lines
3.9 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -passes='loop-load-elim,indvars,loop-distribute' -enable-loop-distribute -S %s | FileCheck %s
define void @test_pr50940(ptr %A, ptr %B) {
; CHECK-LABEL: @test_pr50940(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[UGLYGEP:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
; CHECK-NEXT: br label [[OUTER_HEADER:%.*]]
; CHECK: outer.header:
; CHECK-NEXT: br i1 false, label [[OUTER_LATCH:%.*]], label [[INNER_PH:%.*]]
; CHECK: inner.ph:
; CHECK-NEXT: [[GEP_A_3:%.*]] = getelementptr inbounds i16, ptr [[A]], i64 3
; CHECK-NEXT: br label [[INNER_LVER_CHECK:%.*]]
; CHECK: inner.lver.check:
; CHECK-NEXT: [[UGLYGEP1:%.*]] = getelementptr i8, ptr [[A]], i64 8
; CHECK-NEXT: [[UGLYGEP2:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 2
; CHECK-NEXT: [[BOUND0:%.*]] = icmp ult ptr [[UGLYGEP]], [[UGLYGEP2]]
; CHECK-NEXT: [[BOUND1:%.*]] = icmp ult ptr [[B]], [[UGLYGEP1]]
; CHECK-NEXT: [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
; CHECK-NEXT: br i1 [[FOUND_CONFLICT]], label [[INNER_PH3_LVER_ORIG:%.*]], label [[INNER_PH3_LDIST1:%.*]]
; CHECK: inner.ph3.lver.orig:
; CHECK-NEXT: br label [[INNER_LVER_ORIG:%.*]]
; CHECK: inner.lver.orig:
; CHECK-NEXT: [[IV_LVER_ORIG:%.*]] = phi i16 [ 0, [[INNER_PH3_LVER_ORIG]] ], [ [[IV_NEXT_LVER_ORIG:%.*]], [[INNER_LVER_ORIG]] ]
; CHECK-NEXT: [[L_LVER_ORIG:%.*]] = load <2 x i16>, ptr [[UGLYGEP]], align 1
; CHECK-NEXT: store i16 0, ptr [[GEP_A_3]], align 1
; CHECK-NEXT: store i16 1, ptr [[B]], align 1
; CHECK-NEXT: [[IV_NEXT_LVER_ORIG]] = add nuw nsw i16 [[IV_LVER_ORIG]], 1
; CHECK-NEXT: [[C_1_LVER_ORIG:%.*]] = icmp ult i16 [[IV_LVER_ORIG]], 38
; CHECK-NEXT: br i1 [[C_1_LVER_ORIG]], label [[INNER_LVER_ORIG]], label [[EXIT_LOOPEXIT:%.*]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK: inner.ph3.ldist1:
; CHECK-NEXT: br label [[INNER_LDIST1:%.*]]
; CHECK: inner.ldist1:
; CHECK-NEXT: [[IV_LDIST1:%.*]] = phi i16 [ 0, [[INNER_PH3_LDIST1]] ], [ [[IV_NEXT_LDIST1:%.*]], [[INNER_LDIST1]] ]
; CHECK-NEXT: [[L_LDIST1:%.*]] = load <2 x i16>, ptr [[UGLYGEP]], align 1, !alias.scope [[META2:![0-9]+]], !noalias [[META5:![0-9]+]]
; CHECK-NEXT: store i16 0, ptr [[GEP_A_3]], align 1, !alias.scope [[META2]], !noalias [[META5]]
; CHECK-NEXT: [[IV_NEXT_LDIST1]] = add nuw nsw i16 [[IV_LDIST1]], 1
; CHECK-NEXT: [[C_1_LDIST1:%.*]] = icmp ult i16 [[IV_LDIST1]], 38
; CHECK-NEXT: br i1 [[C_1_LDIST1]], label [[INNER_LDIST1]], label [[INNER_PH3:%.*]]
; CHECK: inner.ph3:
; CHECK-NEXT: br label [[INNER:%.*]]
; CHECK: inner:
; CHECK-NEXT: [[IV:%.*]] = phi i16 [ 0, [[INNER_PH3]] ], [ [[IV_NEXT:%.*]], [[INNER]] ]
; CHECK-NEXT: store i16 1, ptr [[B]], align 1, !alias.scope [[META5]]
; CHECK-NEXT: [[IV_NEXT]] = add nuw nsw i16 [[IV]], 1
; CHECK-NEXT: [[C_1:%.*]] = icmp ult i16 [[IV]], 38
; CHECK-NEXT: br i1 [[C_1]], label [[INNER]], label [[EXIT_LOOPEXIT4:%.*]]
; CHECK: outer.latch:
; CHECK-NEXT: br label [[OUTER_HEADER]]
; CHECK: exit.loopexit:
; CHECK-NEXT: br label [[EXIT:%.*]]
; CHECK: exit.loopexit4:
; CHECK-NEXT: br label [[EXIT]]
; CHECK: exit:
; CHECK-NEXT: ret void
;
entry:
%gep.A.1 = getelementptr inbounds i16, ptr %A, i64 1
br label %outer.header
outer.header:
%gep.A.2 = getelementptr inbounds i16, ptr %gep.A.1, i64 1
br i1 false, label %outer.latch, label %inner.ph
inner.ph: ; preds = %for.body5
%lcssa.gep = phi ptr [ %gep.A.2, %outer.header ]
%gep.A.3 = getelementptr inbounds i16, ptr %A, i64 3
br label %inner
inner:
%iv = phi i16 [ 0, %inner.ph ], [ %iv.next, %inner ]
%l = load <2 x i16>, ptr %lcssa.gep, align 1
store i16 0, ptr %gep.A.3, align 1
store i16 1, ptr %B, align 1
%iv.next = add nuw nsw i16 %iv, 1
%c.1 = icmp ult i16 %iv, 38
br i1 %c.1, label %inner, label %exit
outer.latch:
br label %outer.header
exit:
ret void
}