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Oct 17, 2024
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[NFC][LoopVectorize] Add more simple early exit tests #112529

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333 changes: 333 additions & 0 deletions llvm/test/Transforms/LoopVectorize/AArch64/simple_early_exit.ll
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
; RUN: opt -S < %s -p loop-vectorize | FileCheck %s --check-prefixes=CHECK

target triple = "aarch64-unknown-linux-gnu"

declare void @init_mem(ptr, i64);

define i64 @same_exit_block_pre_inc_use1() #1 {
; CHECK-LABEL: define i64 @same_exit_block_pre_inc_use1(
; CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P1:%.*]] = alloca [1024 x i8], align 4
; CHECK-NEXT: [[P2:%.*]] = alloca [1024 x i8], align 4
; CHECK-NEXT: call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT: call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDEX2:%.*]] = phi i64 [ [[INDEX_NEXT1:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX2]]
; CHECK-NEXT: [[TMP38:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX2]]
; CHECK-NEXT: [[TMP39:%.*]] = load i8, ptr [[ARRAYIDX1]], align 1
; CHECK-NEXT: [[CMP3:%.*]] = icmp eq i8 [[TMP38]], [[TMP39]]
; CHECK-NEXT: br i1 [[CMP3]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK: loop.inc:
; CHECK-NEXT: [[INDEX_NEXT1]] = add i64 [[INDEX2]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT1]], 67
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK: loop.end:
; CHECK-NEXT: [[START_0_LCSSA:%.*]] = phi i64 [ [[INDEX2]], [[LOOP]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT: ret i64 [[START_0_LCSSA]]
;
entry:
%p1 = alloca [1024 x i8]
%p2 = alloca [1024 x i8]
call void @init_mem(ptr %p1, i64 1024)
call void @init_mem(ptr %p2, i64 1024)
br label %loop

loop:
%index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
%arrayidx = getelementptr inbounds i8, ptr %p1, i64 %index
%ld1 = load i8, ptr %arrayidx, align 1
%arrayidx1 = getelementptr inbounds i8, ptr %p2, i64 %index
%ld2 = load i8, ptr %arrayidx1, align 1
%cmp3 = icmp eq i8 %ld1, %ld2
br i1 %cmp3, label %loop.inc, label %loop.end

loop.inc:
%index.next = add i64 %index, 1
%exitcond = icmp ne i64 %index.next, 67
br i1 %exitcond, label %loop, label %loop.end

loop.end:
%retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
ret i64 %retval
}


; In this example the early exit block appears in the list of ExitNotTaken
; SCEVs, but is not computable.
define i64 @same_exit_block_pre_inc_use4() {
; CHECK-LABEL: define i64 @same_exit_block_pre_inc_use4() {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P1:%.*]] = alloca [1024 x i64], align 8
; CHECK-NEXT: [[P2:%.*]] = alloca [1024 x i64], align 8
; CHECK-NEXT: call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT: call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i64, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT: [[LD1:%.*]] = load i64, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT: [[CMP3:%.*]] = icmp ult i64 [[INDEX]], [[LD1]]
; CHECK-NEXT: br i1 [[CMP3]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK: loop.inc:
; CHECK-NEXT: [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP1]], label [[LOOP_END]]
; CHECK: loop.end:
; CHECK-NEXT: [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP1]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT: ret i64 [[RETVAL]]
;
entry:
%p1 = alloca [1024 x i64]
%p2 = alloca [1024 x i64]
call void @init_mem(ptr %p1, i64 1024)
call void @init_mem(ptr %p2, i64 1024)
br label %loop

loop:
%index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %p1, i64 %index
%ld1 = load i64, ptr %arrayidx, align 1
%cmp3 = icmp ult i64 %index, %ld1
br i1 %cmp3, label %loop.inc, label %loop.end

loop.inc:
%index.next = add i64 %index, 1
%exitcond = icmp ne i64 %index.next, 67
br i1 %exitcond, label %loop, label %loop.end

loop.end:
%retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
ret i64 %retval
}


define i64 @loop_contains_safe_call() #1 {
; CHECK-LABEL: define i64 @loop_contains_safe_call(
; CHECK-SAME: ) #[[ATTR0]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P1:%.*]] = alloca [1024 x i8], align 4
; CHECK-NEXT: [[P2:%.*]] = alloca [1024 x i8], align 4
; CHECK-NEXT: call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT: call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDEX2:%.*]] = phi i64 [ [[INDEX_NEXT1:%.*]], [[LOOP_INC1:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds float, ptr [[P1]], i64 [[INDEX2]]
; CHECK-NEXT: [[LD1:%.*]] = load float, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT: [[SQRT:%.*]] = tail call fast float @llvm.sqrt.f32(float [[LD1]])
; CHECK-NEXT: [[CMP:%.*]] = fcmp fast ult float [[SQRT]], 3.000000e+00
; CHECK-NEXT: br i1 [[CMP]], label [[LOOP_INC1]], label [[LOOP_END:%.*]]
; CHECK: loop.inc:
; CHECK-NEXT: [[INDEX_NEXT1]] = add i64 [[INDEX2]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT1]], 67
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP1]], label [[LOOP_END]]
; CHECK: loop.end:
; CHECK-NEXT: [[RETVAL:%.*]] = phi i64 [ [[INDEX2]], [[LOOP1]] ], [ 67, [[LOOP_INC1]] ]
; CHECK-NEXT: ret i64 [[RETVAL]]
;
entry:
%p1 = alloca [1024 x i8]
%p2 = alloca [1024 x i8]
call void @init_mem(ptr %p1, i64 1024)
call void @init_mem(ptr %p2, i64 1024)
br label %loop

loop:
%index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
%arrayidx = getelementptr inbounds float, ptr %p1, i64 %index
%ld1 = load float, ptr %arrayidx, align 1
%sqrt = tail call fast float @llvm.sqrt.f32(float %ld1)
%cmp = fcmp fast ult float %sqrt, 3.0e+00
br i1 %cmp, label %loop.inc, label %loop.end

loop.inc:
%index.next = add i64 %index, 1
%exitcond = icmp ne i64 %index.next, 67
br i1 %exitcond, label %loop, label %loop.end

loop.end:
%retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
ret i64 %retval
}


define i64 @loop_contains_safe_div() #1 {
; CHECK-LABEL: define i64 @loop_contains_safe_div(
; CHECK-SAME: ) #[[ATTR0]] {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P1:%.*]] = alloca [1024 x i8], align 4
; CHECK-NEXT: [[P2:%.*]] = alloca [1024 x i8], align 4
; CHECK-NEXT: call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT: call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT: br label [[LOOP:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT: [[LD1:%.*]] = load i32, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT: [[DIV:%.*]] = udiv i32 [[LD1]], 20000
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[DIV]], 1
; CHECK-NEXT: br i1 [[CMP]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK: loop.inc:
; CHECK-NEXT: [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK: loop.end:
; CHECK-NEXT: [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT: ret i64 [[RETVAL]]
;
entry:
%p1 = alloca [1024 x i8]
%p2 = alloca [1024 x i8]
call void @init_mem(ptr %p1, i64 1024)
call void @init_mem(ptr %p2, i64 1024)
br label %loop

loop:
%index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %p1, i64 %index
%ld1 = load i32, ptr %arrayidx, align 1
%div = udiv i32 %ld1, 20000
%cmp = icmp eq i32 %div, 1
br i1 %cmp, label %loop.inc, label %loop.end

loop.inc:
%index.next = add i64 %index, 1
%exitcond = icmp ne i64 %index.next, 67
br i1 %exitcond, label %loop, label %loop.end

loop.end:
%retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
ret i64 %retval
}


define i64 @loop_contains_load_after_early_exit(ptr dereferenceable(1024) align(8) %p2) {
; DEBUG-LABEL: LV: Checking a loop in 'loop_contains_load_after_early_exit'
; DEBUG: LV: Found an early exit loop with symbolic max backedge taken count: 63
; DEBUG-NEXT: LV: We can vectorize this loop!
; DEBUG-NEXT: LV: Not vectorizing: Auto-vectorization of loops with uncountable early exit is not yet supported.
; CHECK-LABEL: define i64 @loop_contains_load_after_early_exit(
; CHECK-SAME: ptr align 8 dereferenceable(1024) [[P2:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P1:%.*]] = alloca [1024 x i8], align 4
; CHECK-NEXT: call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT: br label [[LOOP1:%.*]]
; CHECK: loop:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT: [[LD1:%.*]] = load i32, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[LD1]], 1
; CHECK-NEXT: br i1 [[CMP]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK: loop.inc:
; CHECK-NEXT: [[ARRAYIDX2:%.*]] = getelementptr inbounds i64, ptr [[P2]], i64 [[INDEX]]
; CHECK-NEXT: [[LD2:%.*]] = load i64, ptr [[ARRAYIDX2]], align 8
; CHECK-NEXT: [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT: [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT: br i1 [[EXITCOND]], label [[LOOP1]], label [[LOOP_END]]
; CHECK: loop.end:
; CHECK-NEXT: [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP1]] ], [ [[LD2]], [[LOOP_INC]] ]
; CHECK-NEXT: ret i64 [[RETVAL]]
;
entry:
%p1 = alloca [1024 x i8]
call void @init_mem(ptr %p1, i64 1024)
br label %loop

loop:
%index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
%arrayidx = getelementptr inbounds i32, ptr %p1, i64 %index
%ld1 = load i32, ptr %arrayidx, align 1
%cmp = icmp eq i32 %ld1, 1
br i1 %cmp, label %loop.inc, label %loop.end

loop.inc:
%arrayidx2 = getelementptr inbounds i64, ptr %p2, i64 %index
%ld2 = load i64, ptr %arrayidx2, align 8
%index.next = add i64 %index, 1
%exitcond = icmp ne i64 %index.next, 67
br i1 %exitcond, label %loop, label %loop.end

loop.end:
%retval = phi i64 [ %index, %loop ], [ %ld2, %loop.inc ]
ret i64 %retval
}


; The form of the induction variables requires SCEV predicates.
define i32 @diff_exit_block_needs_scev_check(i32 %end) {
; DEBUG-LABEL: LV: Checking a loop in 'diff_exit_block_needs_scev_check'
; DEBUG: Found an early exit loop with symbolic max backedge taken count: (-1 + (1 umax (zext i10 (trunc i32 %end to i10) to i32)))<nsw>
; DEBUG-NEXT: LV: We can vectorize this loop!
; DEBUG-NEXT: LV: Not vectorizing: Auto-vectorization of loops with uncountable early exit is not yet supported.
; CHECK-LABEL: define i32 @diff_exit_block_needs_scev_check(
; CHECK-SAME: i32 [[END:%.*]]) {
; CHECK-NEXT: entry:
; CHECK-NEXT: [[P1:%.*]] = alloca [1024 x i32], align 4
; CHECK-NEXT: [[P2:%.*]] = alloca [1024 x i32], align 4
; CHECK-NEXT: call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT: call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT: [[END_CLAMPED:%.*]] = and i32 [[END]], 1023
; CHECK-NEXT: br label [[FOR_BODY1:%.*]]
; CHECK: for.body:
; CHECK-NEXT: [[IND:%.*]] = phi i8 [ [[IND_NEXT:%.*]], [[FOR_INC:%.*]] ], [ 0, [[ENTRY:%.*]] ]
; CHECK-NEXT: [[GEP_IND:%.*]] = phi i64 [ [[GEP_IND_NEXT:%.*]], [[FOR_INC]] ], [ 0, [[ENTRY]] ]
; CHECK-NEXT: [[ARRAYIDX1:%.*]] = getelementptr inbounds i32, ptr [[P1]], i64 [[GEP_IND]]
; CHECK-NEXT: [[TMP0:%.*]] = load i32, ptr [[ARRAYIDX1]], align 4
; CHECK-NEXT: [[ARRAYIDX2:%.*]] = getelementptr inbounds i32, ptr [[P2]], i64 [[GEP_IND]]
; CHECK-NEXT: [[TMP1:%.*]] = load i32, ptr [[ARRAYIDX2]], align 4
; CHECK-NEXT: [[CMP_EARLY:%.*]] = icmp eq i32 [[TMP0]], [[TMP1]]
; CHECK-NEXT: br i1 [[CMP_EARLY]], label [[FOUND:%.*]], label [[FOR_INC]]
; CHECK: for.inc:
; CHECK-NEXT: [[IND_NEXT]] = add i8 [[IND]], 1
; CHECK-NEXT: [[CONV:%.*]] = zext i8 [[IND_NEXT]] to i32
; CHECK-NEXT: [[GEP_IND_NEXT]] = add i64 [[GEP_IND]], 1
; CHECK-NEXT: [[CMP:%.*]] = icmp ult i32 [[CONV]], [[END_CLAMPED]]
; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY1]], label [[EXIT:%.*]]
; CHECK: found:
; CHECK-NEXT: ret i32 1
; CHECK: exit:
; CHECK-NEXT: ret i32 0
;
entry:
%p1 = alloca [1024 x i32]
%p2 = alloca [1024 x i32]
call void @init_mem(ptr %p1, i64 1024)
call void @init_mem(ptr %p2, i64 1024)
%end.clamped = and i32 %end, 1023
br label %for.body

for.body:
%ind = phi i8 [ %ind.next, %for.inc ], [ 0, %entry ]
%gep.ind = phi i64 [ %gep.ind.next, %for.inc ], [ 0, %entry ]
%arrayidx1 = getelementptr inbounds i32, ptr %p1, i64 %gep.ind
%0 = load i32, ptr %arrayidx1, align 4
%arrayidx2 = getelementptr inbounds i32, ptr %p2, i64 %gep.ind
%1 = load i32, ptr %arrayidx2, align 4
%cmp.early = icmp eq i32 %0, %1
br i1 %cmp.early, label %found, label %for.inc

for.inc:
%ind.next = add i8 %ind, 1
%conv = zext i8 %ind.next to i32
%gep.ind.next = add i64 %gep.ind, 1
%cmp = icmp ult i32 %conv, %end.clamped
br i1 %cmp, label %for.body, label %exit

found:
ret i32 1

exit:
ret i32 0
}


declare i32 @foo(i32) readonly
declare <vscale x 4 x i32> @foo_vec(<vscale x 4 x i32>)

attributes #0 = { "vector-function-abi-variant"="_ZGVsNxv_foo(foo_vec)" }
attributes #1 = { "target-features"="+sve" vscale_range(1,16) }
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