[llvm] aac6629 - [ConstraintElimination] Add initial usub.with.overflow tests.

Florian Hahn via llvm-commits llvm-commits at lists.llvm.org
Mon Sep 26 08:44:53 PDT 2022


Author: Zain Jaffal
Date: 2022-09-26T16:44:36+01:00
New Revision: aac6629f6dcdb1ed5c34ef2c317e93b927a11b4a

URL: https://github.com/llvm/llvm-project/commit/aac6629f6dcdb1ed5c34ef2c317e93b927a11b4a
DIFF: https://github.com/llvm/llvm-project/commit/aac6629f6dcdb1ed5c34ef2c317e93b927a11b4a.diff

LOG: [ConstraintElimination] Add initial usub.with.overflow tests.

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

Reviewed By: fhahn, fcloutier

Differential Revision: https://reviews.llvm.org/D134038

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

Modified: 
    

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/ConstraintElimination/usub-with-overflow.ll b/llvm/test/Transforms/ConstraintElimination/usub-with-overflow.ll
new file mode 100644
index 0000000000000..2cc6ec19cfd1d
--- /dev/null
+++ b/llvm/test/Transforms/ConstraintElimination/usub-with-overflow.ll
@@ -0,0 +1,307 @@
+; 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
+}
+


        


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