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Differential D153936

[LV] Add tests for select-cmp reduction pattern. (NFC)
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Authored by Mel-Chen on Jun 27 2023, 8:36 PM.

Details

Reviewers
fhahn
shiva0217
artagnon
Commits
rG4ddc1745a84d: [LV] Add tests for select-cmp reduction pattern. (NFC)
Summary

The test cases for selecting increasing integer induction variable.

Diff Detail

Event Timeline

Mel-Chen created this revision.Jun 27 2023, 8:36 PM
Herald added a project: Restricted Project. · View Herald TranscriptJun 27 2023, 8:36 PM
Herald added a subscriber: artagnon. · View Herald Transcript
Mel-Chen requested review of this revision.Jun 27 2023, 8:36 PM
Herald added a project: Restricted Project. · View Herald TranscriptJun 27 2023, 8:36 PM
Herald added a subscriber: llvm-commits. · View Herald Transcript
Mel-Chen added a child revision: D150851: [LoopVectorize] Vectorize select-cmp reduction pattern for increasing integer induction variable.Jun 27 2023, 8:45 PM
Mel-Chen added reviewers: fhahn, shiva0217, artagnon.
Herald added a subscriber: StephenFan. · View Herald TranscriptJun 27 2023, 8:46 PM
Harbormaster completed remote builds in B241675: Diff 535224.Jun 27 2023, 9:31 PM
Mel-Chen added a comment.Jul 10 2023, 2:25 AM

ping

Herald added a subscriber: wangpc. · View Herald TranscriptJul 10 2023, 2:25 AM
fhahn added inline comments.Jul 10 2023, 12:47 PM
llvm/test/Transforms/LoopVectorize/iv-select-cmp-no-wrap.ll
12

Should we also have tests with different induction start values (constant and variable)? Would be good to adjust the name of the phis to make clearer what's the induction and what's the select reduction.

nit: personally I find it easier to read if the incoming value from the preheader comes first.

llvm/test/Transforms/LoopVectorize/iv-select-cmp.ll
28

What does _const_2 stand for here?

Mel-Chen added inline comments.Jul 10 2023, 10:53 PM
llvm/test/Transforms/LoopVectorize/iv-select-cmp-no-wrap.ll
12

Sure. I will add a new test case into iv-select-cmp.ll, and it will be a negative case for D150851.

llvm/test/Transforms/LoopVectorize/iv-select-cmp.ll
28

There is no special meaning. _const is only used to indicate that the value is compared to a constant, and _2 is just a serial number indicating they are similar tests. The difference between const_2 and const_1 is %cond = select i1 %cmp2, i64 %idx.09, i64 %i.010, while the difference between const_3 and const_1 is %idx.09 = phi i64 [ %cond, %for.body ], [ %ii, %entry ].

Mel-Chen updated this revision to Diff 538965.Jul 11 2023, 1:56 AM

Changes:

  • Change the name of phi
  • Add a negative test case
Harbormaster completed remote builds in B244376: Diff 538965.Jul 11 2023, 2:47 AM
shiva0217 accepted this revision.Jul 12 2023, 11:11 PM

LGTM

llvm/test/Transforms/LoopVectorize/iv-select-cmp.ll
164

Perhaps select_icmp_min_valid_iv_start ?

This revision is now accepted and ready to land.Jul 12 2023, 11:11 PM
Mel-Chen updated this revision to Diff 541854.Jul 18 2023, 11:54 PM

Changes:

  • Replace select_icmp_min_iv_start_value with select_icmp_min_valid_iv_start
fhahn accepted this revision.Jul 19 2023, 2:47 AM

LGTM, thanks!

llvm/test/Transforms/LoopVectorize/iv-select-cmp.ll
36

nit: can also drop .010 and .09 from the value names

50

nit: would select_icmp_const_3-> select_icmp_const_3_variable_rdx_start be more descriptive?

116

nit: ii better named rdx.start or something like that

nit: would @select_icmp -> @select_icmp_variable_rdx_start be more descriptive?

Harbormaster completed remote builds in B246441: Diff 541854.Jul 19 2023, 2:53 AM
Mel-Chen updated this revision to Diff 542285.Jul 19 2023, 8:15 PM
Mel-Chen marked an inline comment as done.

Changes:

  • Drop the suffix of variable name
  • Replace select_icmp_const_3 with select_icmp_const_3_variable_rdx_start
  • Replace %ii with %rdx.start
This revision was landed with ongoing or failed builds.Jul 19 2023, 8:17 PM
Closed by commit rG4ddc1745a84d: [LV] Add tests for select-cmp reduction pattern. (NFC) (authored by Mel-Chen). · Explain Why
This revision was automatically updated to reflect the committed changes.
Mel-Chen added a commit: rG4ddc1745a84d: [LV] Add tests for select-cmp reduction pattern. (NFC).

Revision Contents

PathSize
llvm/
test/
Transforms/
LoopVectorize/
97 lines
289 lines

Diff 542286

llvm/test/Transforms/LoopVectorize/iv-select-cmp-no-wrap.ll

  • This file was added.
; RUN: opt -passes=loop-vectorize -force-vector-interleave=1 -force-vector-width=4 -S < %s | FileCheck %s --check-prefix=CHECK
define i64 @select_icmp_nuw_nsw(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %ii, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_nuw_nsw
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %ii, %entry ]
fhahnUnsubmitted
Not Done
ReplyInline Actions

Should we also have tests with different induction start values (constant and variable)? Would be good to adjust the name of the phis to make clearer what's the induction and what's the select reduction.

nit: personally I find it easier to read if the incoming value from the preheader comes first.

fhahn: Should we also have tests with different induction start values (constant and variable)? Would…
Mel-ChenAuthorUnsubmitted
Done
ReplyInline Actions

Sure. I will add a new test case into iv-select-cmp.ll, and it will be a negative case for D150851.

Mel-Chen: Sure. I will add a new test case into `iv-select-cmp.ll`, and it will be a negative case for…
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_icmp_nsw(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %ii, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_nsw
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %ii, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_icmp_nuw(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %ii, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_nuw
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %ii, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_icmp_noflag(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %ii, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_noflag
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %ii, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}

llvm/test/Transforms/LoopVectorize/iv-select-cmp.ll

  • This file was added.
; RUN: opt -passes=loop-vectorize -force-vector-interleave=1 -force-vector-width=4 -S < %s | FileCheck %s --check-prefix=CHECK
; RUN: opt -passes=loop-vectorize -force-vector-interleave=4 -force-vector-width=4 -S < %s | FileCheck %s --check-prefix=CHECK
; RUN: opt -passes=loop-vectorize -force-vector-interleave=4 -force-vector-width=1 -S < %s | FileCheck %s --check-prefix=CHECK
define i64 @select_icmp_const_1(ptr nocapture readonly %a, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_const_1
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ 3, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%cmp2 = icmp eq i64 %0, 3
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_icmp_const_2(ptr nocapture readonly %a, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_const_2
fhahnUnsubmitted
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What does _const_2 stand for here?

fhahn: What does `_const_2` stand for here?
Mel-ChenAuthorUnsubmitted
Done
ReplyInline Actions

There is no special meaning. _const is only used to indicate that the value is compared to a constant, and _2 is just a serial number indicating they are similar tests. The difference between const_2 and const_1 is %cond = select i1 %cmp2, i64 %idx.09, i64 %i.010, while the difference between const_3 and const_1 is %idx.09 = phi i64 [ %cond, %for.body ], [ %ii, %entry ].

Mel-Chen: There is no special meaning. `_const` is only used to indicate that the value is compared to a…
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ 3, %entry ]
fhahnUnsubmitted
Not Done
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nit: can also drop .010 and .09 from the value names

fhahn: nit: can also drop `.010` and `.09` from the value names
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%cmp2 = icmp eq i64 %0, 3
%cond = select i1 %cmp2, i64 %rdx, i64 %iv
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_icmp_const_3_variable_rdx_start(ptr nocapture readonly %a, i64 %rdx.start, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_const_3_variable_rdx_start
fhahnUnsubmitted
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nit: would select_icmp_const_3-> select_icmp_const_3_variable_rdx_start be more descriptive?

fhahn: nit: would `select_icmp_const_3-> select_icmp_const_3_variable_rdx_start` be more descriptive?
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %rdx.start, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%cmp2 = icmp eq i64 %0, 3
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_fcmp_const_fast(ptr nocapture readonly %a, i64 %n) {
; CHECK-LABEL: define i64 @select_fcmp_const_fast
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ 2, %entry ]
%arrayidx = getelementptr inbounds float, ptr %a, i64 %iv
%0 = load float, ptr %arrayidx, align 4
%cmp2 = fcmp fast ueq float %0, 3.0
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_fcmp_const(ptr nocapture readonly %a, i64 %n) {
; CHECK-LABEL: define i64 @select_fcmp_const
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ 2, %entry ]
%arrayidx = getelementptr inbounds float, ptr %a, i64 %iv
%0 = load float, ptr %arrayidx, align 4
%cmp2 = fcmp ueq float %0, 3.0
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_icmp(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %rdx.start, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp
fhahnUnsubmitted
Not Done
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nit: ii better named rdx.start or something like that

nit: would @select_icmp -> @select_icmp_variable_rdx_start be more descriptive?

fhahn: nit: `ii` better named `rdx.start` or something like that nit: would `@select_icmp` ->…
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %rdx.start, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_fcmp(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %rdx.start, i64 %n) {
; CHECK-LABEL: define i64 @select_fcmp
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %rdx.start, %entry ]
%arrayidx = getelementptr inbounds float, ptr %a, i64 %iv
%0 = load float, ptr %arrayidx, align 4
%arrayidx1 = getelementptr inbounds float, ptr %b, i64 %iv
%1 = load float, ptr %arrayidx1, align 4
%cmp2 = fcmp ogt float %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @select_icmp_min_valid_iv_start(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %rdx.start, i64 %n) {
; CHECK-LABEL: define i64 @select_icmp_min_valid_iv_start
shiva0217Unsubmitted
Done
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Perhaps select_icmp_min_valid_iv_start ?

shiva0217: Perhaps select_icmp_min_valid_iv_start ?
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv.j = phi i64 [ %inc3, %for.body ], [ -9223372036854775807, %entry]
%iv.i = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %rdx.start, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv.i
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv.i
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv.j, i64 %rdx
%inc = add nuw nsw i64 %iv.i, 1
%inc3 = add nsw i64 %iv.j, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
; Negative tests
define float @not_vectorized_select_float_induction_icmp(ptr nocapture readonly %a, ptr nocapture readonly %b, float %rdx.start, i64 %n) {
; CHECK-LABEL: @not_vectorized_select_float_induction_icmp
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%fiv = phi float [ %conv3, %for.body ], [ 0.000000e+00, %entry ]
%rdx = phi float [ %cond, %for.body ], [ %rdx.start, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, float %fiv, float %rdx
%conv3 = fadd float %fiv, 1.000000e+00
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret float %cond
}
define i64 @not_vectorized_select_decreasing_induction_icmp(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %rdx.start, i64 %n) {
; CHECK-LABEL: @not_vectorized_select_decreasing_induction_icmp
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%i.0.in10 = phi i64 [ %iv, %for.body ], [ %n, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %rdx.start, %entry ]
%iv = add nsw i64 %i.0.in10, -1
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%cmp = icmp ugt i64 %i.0.in10, 1
br i1 %cmp, label %for.body, label %exit
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @not_vectorized_select_icmp_iv_out_of_bound(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %rdx.start, i64 %n) {
; CHECK-LABEL: @not_vectorized_select_icmp_iv_out_of_bound
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv.j = phi i64 [ %inc3, %for.body ], [ -9223372036854775808, %entry]
%iv.i = phi i64 [ %inc, %for.body ], [ 0, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %rdx.start, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv.i
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv.i
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv.j, i64 %rdx
%inc = add nuw nsw i64 %iv.i, 1
%inc3 = add nsw i64 %iv.j, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}
define i64 @not_vectorized_select_icmp_non_const_iv_start_value(ptr nocapture readonly %a, ptr nocapture readonly %b, i64 %ivstart, i64 %rdx.start, i64 %n) {
; CHECK-LABEL: define i64 @not_vectorized_select_icmp_non_const_iv_start_value
; CHECK-NOT: vector.body:
;
entry:
br label %for.body
for.body: ; preds = %entry, %for.body
%iv = phi i64 [ %inc, %for.body ], [ %ivstart, %entry ]
%rdx = phi i64 [ %cond, %for.body ], [ %rdx.start, %entry ]
%arrayidx = getelementptr inbounds i64, ptr %a, i64 %iv
%0 = load i64, ptr %arrayidx, align 8
%arrayidx1 = getelementptr inbounds i64, ptr %b, i64 %iv
%1 = load i64, ptr %arrayidx1, align 8
%cmp2 = icmp sgt i64 %0, %1
%cond = select i1 %cmp2, i64 %iv, i64 %rdx
%inc = add nuw nsw i64 %iv, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %exit, label %for.body
exit: ; preds = %for.body
ret i64 %cond
}