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Differential D134038

[ConstraintElimination] Add initial usub.with.overflow tests.
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Authored by zjaffal on Sep 16 2022, 6:26 AM.

Details

Reviewers
fhahn
fcloutier
rapidsna
spatel
nikic
reames
Commits
rGaac6629f6dcd: [ConstraintElimination] Add initial usub.with.overflow tests.
Summary

Optimizations can be used to eliminate unecessary overflow checks. This patch introduces some test cases where the checks can be safely removed

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Event Timeline

zjaffal created this revision.Sep 16 2022, 6:26 AM
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zjaffal requested review of this revision.Sep 16 2022, 6:26 AM
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fhahn accepted this revision.Sep 16 2022, 7:05 AM

LGTM, thanks!

This revision is now accepted and ready to land.Sep 16 2022, 7:05 AM
zjaffal updated this revision to Diff 460742.Sep 16 2022, 7:05 AM

Fix usub_no_overflow_due_to_or_conds and usub_no_overflow_due_to_or_conds_sub_result_not_used to use the correct exit condition

Harbormaster completed remote builds in B187138: Diff 460742.Sep 16 2022, 8:08 AM
fcloutier accepted this revision.Sep 16 2022, 8:51 AM
This revision was landed with ongoing or failed builds.Sep 26 2022, 8:44 AM
Closed by commit rGaac6629f6dcd: [ConstraintElimination] Add initial usub.with.overflow tests. (authored by zjaffal, committed by fhahn). · Explain Why
This revision was automatically updated to reflect the committed changes.
fhahn added a commit: rGaac6629f6dcd: [ConstraintElimination] Add initial usub.with.overflow tests..

Revision Contents

PathSize
llvm/
test/
Transforms/
ConstraintElimination/
307 lines

Diff 462925

llvm/test/Transforms/ConstraintElimination/usub-with-overflow.ll

  • This file was added.
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -passes=constraint-elimination -S %s | FileCheck %s
declare { i8, i1 } @llvm.usub.with.overflow.i8(i8, i8)
define i8 @usub_no_overflow_due_to_cmp_condition(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_no_overflow_due_to_cmp_condition(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp uge i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: br i1 [[C_1]], label [[MATH:%.*]], label [[EXIT_FAIL:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp uge i8 %b, %a
br i1 %c.1, label %math, label %exit.fail
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}
define i8 @usub_no_overflow_due_to_cmp_condition2(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_no_overflow_due_to_cmp_condition2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: br i1 [[C_1]], label [[EXIT_FAIL:%.*]], label [[MATH:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp ule i8 %b, %a
br i1 %c.1, label %exit.fail, label %math
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}
declare void @use_res({ i8, i1 })
define i8 @sub_no_overflow_due_to_cmp_condition_result_used(i8 %a, i8 %b) {
; CHECK-LABEL: @sub_no_overflow_due_to_cmp_condition_result_used(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: br i1 [[C_1]], label [[EXIT_FAIL:%.*]], label [[MATH:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: call void @use_res({ i8, i1 } [[OP]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp ule i8 %b, %a
br i1 %c.1, label %exit.fail, label %math
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
call void @use_res({ i8, i1 } %op)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}
define i8 @usub_no_overflow_due_to_or_conds(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_no_overflow_due_to_or_conds(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: [[C_2:%.*]] = icmp ule i8 [[A]], 0
; CHECK-NEXT: [[OR:%.*]] = or i1 [[C_2]], [[C_1]]
; CHECK-NEXT: br i1 [[OR]], label [[EXIT_FAIL:%.*]], label [[MATH:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp ule i8 %b, %a
%c.2 = icmp ule i8 %a, 0
%or = or i1 %c.2, %c.1
br i1 %or, label %exit.fail, label %math
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}
define i8 @usub_no_overflow_due_to_or_conds_sub_result_not_used(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_no_overflow_due_to_or_conds_sub_result_not_used(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp ule i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: [[C_2:%.*]] = icmp ule i8 [[A]], 0
; CHECK-NEXT: [[OR:%.*]] = or i1 [[C_2]], [[C_1]]
; CHECK-NEXT: br i1 [[OR]], label [[EXIT_FAIL:%.*]], label [[MATH:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: ret i8 20
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp ule i8 %b, %a
%c.2 = icmp ule i8 %a, 0
%or = or i1 %c.2, %c.1
br i1 %or, label %exit.fail, label %math
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
ret i8 20
exit.fail:
ret i8 0
}
define i8 @usub_no_overflow_due_to_and_conds(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_no_overflow_due_to_and_conds(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp uge i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: [[C_2:%.*]] = icmp uge i8 [[A]], -1
; CHECK-NEXT: [[AND:%.*]] = and i1 [[C_2]], [[C_1]]
; CHECK-NEXT: br i1 [[AND]], label [[MATH:%.*]], label [[EXIT_FAIL:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp uge i8 %b, %a
%c.2 = icmp uge i8 %a, -1
%and = and i1 %c.2, %c.1
br i1 %and, label %math, label %exit.fail
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}
define i8 @usub_may_overflow1(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_may_overflow1(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp uge i8 [[A:%.*]], 0
; CHECK-NEXT: br i1 [[C_1]], label [[MATH:%.*]], label [[EXIT_FAIL:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B:%.*]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp uge i8 %a, 0
br i1 %c.1, label %math, label %exit.fail
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}
define i8 @usub_may_overflow2(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_may_overflow2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp sge i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: br i1 [[C_1]], label [[MATH:%.*]], label [[EXIT_FAIL:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp sge i8 %b, %a
br i1 %c.1, label %math, label %exit.fail
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}
define i8 @usub_may_overflow3(i8 %a, i8 %b) {
; CHECK-LABEL: @usub_may_overflow3(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[C_1:%.*]] = icmp slt i8 [[B:%.*]], [[A:%.*]]
; CHECK-NEXT: br i1 [[C_1]], label [[EXIT_FAIL:%.*]], label [[MATH:%.*]]
; CHECK: math:
; CHECK-NEXT: [[OP:%.*]] = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 [[B]], i8 [[A]])
; CHECK-NEXT: [[STATUS:%.*]] = extractvalue { i8, i1 } [[OP]], 1
; CHECK-NEXT: br i1 [[STATUS]], label [[EXIT_FAIL]], label [[EXIT_OK:%.*]]
; CHECK: exit.ok:
; CHECK-NEXT: [[RES:%.*]] = extractvalue { i8, i1 } [[OP]], 0
; CHECK-NEXT: ret i8 [[RES]]
; CHECK: exit.fail:
; CHECK-NEXT: ret i8 0
;
entry:
%c.1 = icmp slt i8 %b, %a
br i1 %c.1, label %exit.fail, label %math
math:
%op = tail call { i8, i1 } @llvm.usub.with.overflow.i8(i8 %b, i8 %a)
%status = extractvalue { i8, i1 } %op, 1
br i1 %status, label %exit.fail, label %exit.ok
exit.ok:
%res = extractvalue { i8, i1 } %op, 0
ret i8 %res
exit.fail:
ret i8 0
}