llvm-project/llvm/test/Transforms/LoopVectorize/reduction-inloop-min-max.ll
Florian Hahn 50b9ca4dda
[VPlan] Simplify Plan's entry in removeBranchOnConst. (#154510)
After https://github.com/llvm/llvm-project/pull/153643, there may be a
BranchOnCond with constant condition in the entry block.

Simplify those in removeBranchOnConst. This removes a number of
redundant conditional branch from entry blocks.

In some cases, it may also make the original scalar loop unreachable,
because we know it will never execute. In that case, we need to remove
the loop from LoopInfo, because all unreachable blocks may dominate each
other, making LoopInfo invalid. In those cases, we can also completely
remove the loop, for which I'll share a follow-up patch.

Depends on https://github.com/llvm/llvm-project/pull/153643.

PR: https://github.com/llvm/llvm-project/pull/154510
2025-09-18 19:25:05 +01:00

281 lines
13 KiB
LLVM

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
; RUN: opt < %s -passes=loop-vectorize,dce,instcombine -force-vector-interleave=1 -force-vector-width=4 -prefer-inloop-reductions -S | FileCheck %s
define i32 @reduction_smin(ptr nocapture %A, ptr nocapture %B) {
; CHECK-LABEL: define i32 @reduction_smin
; CHECK-SAME: (ptr captures(none) [[A:%.*]], ptr captures(none) [[B:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi i32 [ 1000, [[VECTOR_PH]] ], [ [[RDX_MINMAX:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[INDEX]]
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP0]], align 4
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.vector.reduce.smin.v4i32(<4 x i32> [[WIDE_LOAD]])
; CHECK-NEXT: [[RDX_MINMAX]] = call i32 @llvm.smin.i32(i32 [[TMP1]], i32 [[VEC_PHI]])
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], 256
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: br label [[FOR_END:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: br i1 poison, label [[FOR_END]], label [[FOR_BODY]]
; CHECK: for.end:
; CHECK-NEXT: ret i32 [[RDX_MINMAX]]
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
%result.08 = phi i32 [ %v0, %for.body ], [ 1000, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv
%l0 = load i32, ptr %arrayidx, align 4
%c0 = icmp slt i32 %result.08, %l0
%v0 = select i1 %c0, i32 %result.08, i32 %l0
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 256
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
%result.0.lcssa = phi i32 [ %v0, %for.body ]
ret i32 %result.0.lcssa
}
define i32 @reduction_smin_select_ops_flipped(ptr nocapture %A, ptr nocapture %B) {
; CHECK-LABEL: define i32 @reduction_smin_select_ops_flipped
; CHECK-SAME: (ptr captures(none) [[A:%.*]], ptr captures(none) [[B:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi i32 [ 1000, [[VECTOR_PH]] ], [ [[RDX_MINMAX:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[INDEX]]
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP0]], align 4
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.vector.reduce.smax.v4i32(<4 x i32> [[WIDE_LOAD]])
; CHECK-NEXT: [[RDX_MINMAX]] = call i32 @llvm.smax.i32(i32 [[TMP1]], i32 [[VEC_PHI]])
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], 256
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP3:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: br label [[FOR_END:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: br i1 poison, label [[FOR_END]], label [[FOR_BODY]]
; CHECK: for.end:
; CHECK-NEXT: ret i32 [[RDX_MINMAX]]
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
%result.08 = phi i32 [ %v0, %for.body ], [ 1000, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv
%l0 = load i32, ptr %arrayidx, align 4
%c0 = icmp slt i32 %result.08, %l0
%v0 = select i1 %c0, i32 %l0, i32 %result.08
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 256
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
%result.0.lcssa = phi i32 [ %v0, %for.body ]
ret i32 %result.0.lcssa
}
define i32 @reduction_smin_intrinsic(ptr nocapture %A, ptr nocapture %B) {
; CHECK-LABEL: define i32 @reduction_smin_intrinsic
; CHECK-SAME: (ptr captures(none) [[A:%.*]], ptr captures(none) [[B:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <4 x i32> [ splat (i32 1000), [[VECTOR_PH]] ], [ [[TMP1:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[INDEX]]
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP0]], align 4
; CHECK-NEXT: [[TMP1]] = call <4 x i32> @llvm.smin.v4i32(<4 x i32> [[VEC_PHI]], <4 x i32> [[WIDE_LOAD]])
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], 256
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: br label [[FOR_END:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: br i1 poison, label [[FOR_END]], label [[FOR_BODY]]
; CHECK: for.end:
; CHECK-NEXT: [[TMP3:%.*]] = call i32 @llvm.vector.reduce.smin.v4i32(<4 x i32> [[TMP1]])
; CHECK-NEXT: ret i32 [[TMP3]]
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
%result.08 = phi i32 [ %v0, %for.body ], [ 1000, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv
%l0 = load i32, ptr %arrayidx, align 4
%v0 = call i32 @llvm.smin.i32(i32 %result.08, i32 %l0)
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 256
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
%result.0.lcssa = phi i32 [ %v0, %for.body ]
ret i32 %result.0.lcssa
}
declare i32 @llvm.smin.i32(i32, i32)
define i32 @reduction_umax(ptr nocapture %A, ptr nocapture %B) {
; CHECK-LABEL: define i32 @reduction_umax
; CHECK-SAME: (ptr captures(none) [[A:%.*]], ptr captures(none) [[B:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi i32 [ 1000, [[VECTOR_PH]] ], [ [[RDX_MINMAX:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[INDEX]]
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP0]], align 4
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.vector.reduce.umax.v4i32(<4 x i32> [[WIDE_LOAD]])
; CHECK-NEXT: [[RDX_MINMAX]] = call i32 @llvm.umax.i32(i32 [[TMP1]], i32 [[VEC_PHI]])
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], 256
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: br label [[FOR_END:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: br i1 poison, label [[FOR_END]], label [[FOR_BODY]]
; CHECK: for.end:
; CHECK-NEXT: ret i32 [[RDX_MINMAX]]
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
%result.08 = phi i32 [ %v0, %for.body ], [ 1000, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv
%l0 = load i32, ptr %arrayidx, align 4
%c0 = icmp ugt i32 %result.08, %l0
%v0 = select i1 %c0, i32 %result.08, i32 %l0
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 256
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
%result.0.lcssa = phi i32 [ %v0, %for.body ]
ret i32 %result.0.lcssa
}
define i32 @reduction_umax_select_ops_flipped(ptr nocapture %A, ptr nocapture %B) {
; CHECK-LABEL: define i32 @reduction_umax_select_ops_flipped
; CHECK-SAME: (ptr captures(none) [[A:%.*]], ptr captures(none) [[B:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi i32 [ 1000, [[VECTOR_PH]] ], [ [[RDX_MINMAX:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[INDEX]]
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP0]], align 4
; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.vector.reduce.umin.v4i32(<4 x i32> [[WIDE_LOAD]])
; CHECK-NEXT: [[RDX_MINMAX]] = call i32 @llvm.umin.i32(i32 [[TMP1]], i32 [[VEC_PHI]])
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], 256
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP6:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: br label [[FOR_END:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: br i1 poison, label [[FOR_END]], label [[FOR_BODY]]
; CHECK: for.end:
; CHECK-NEXT: ret i32 [[RDX_MINMAX]]
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
%result.08 = phi i32 [ %v0, %for.body ], [ 1000, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv
%l0 = load i32, ptr %arrayidx, align 4
%c0 = icmp ugt i32 %result.08, %l0
%v0 = select i1 %c0, i32 %l0, i32 %result.08
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 256
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
%result.0.lcssa = phi i32 [ %v0, %for.body ]
ret i32 %result.0.lcssa
}
define i32 @reduction_umax_intrinsic(ptr nocapture %A, ptr nocapture %B) {
; CHECK-LABEL: define i32 @reduction_umax_intrinsic
; CHECK-SAME: (ptr captures(none) [[A:%.*]], ptr captures(none) [[B:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: br label [[VECTOR_BODY:%.*]]
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI:%.*]] = phi <4 x i32> [ splat (i32 1000), [[VECTOR_PH]] ], [ [[TMP1:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds i32, ptr [[A]], i64 [[INDEX]]
; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP0]], align 4
; CHECK-NEXT: [[TMP1]] = call <4 x i32> @llvm.umax.v4i32(<4 x i32> [[VEC_PHI]], <4 x i32> [[WIDE_LOAD]])
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], 256
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP7:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: br label [[FOR_END:%.*]]
; CHECK: scalar.ph:
; CHECK-NEXT: br label [[FOR_BODY:%.*]]
; CHECK: for.body:
; CHECK-NEXT: br i1 poison, label [[FOR_END]], label [[FOR_BODY]]
; CHECK: for.end:
; CHECK-NEXT: [[TMP3:%.*]] = call i32 @llvm.vector.reduce.umax.v4i32(<4 x i32> [[TMP1]])
; CHECK-NEXT: ret i32 [[TMP3]]
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
%result.08 = phi i32 [ %v0, %for.body ], [ 1000, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv
%l0 = load i32, ptr %arrayidx, align 4
%v0 = call i32 @llvm.umax.i32(i32 %result.08, i32 %l0)
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 256
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
%result.0.lcssa = phi i32 [ %v0, %for.body ]
ret i32 %result.0.lcssa
}
declare i32 @llvm.umax.i32(i32, i32)