[llvm] 301fe08 - [ConstraintElimination] Add test where ssub result is not used.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2022-05-11T16:10:25+01:00
New Revision: 301fe084bff388a734d284cf4db9cb44f29d99c0

URL: https://github.com/llvm/llvm-project/commit/301fe084bff388a734d284cf4db9cb44f29d99c0
DIFF: https://github.com/llvm/llvm-project/commit/301fe084bff388a734d284cf4db9cb44f29d99c0.diff

LOG: [ConstraintElimination] Add test where ssub result is not used.

Extra tests for D125264.

Added: 
    

Modified: 
    llvm/test/Transforms/ConstraintElimination/ssub-with-overflow.ll

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/ConstraintElimination/ssub-with-overflow.ll b/llvm/test/Transforms/ConstraintElimination/ssub-with-overflow.ll
index 05eb713ea9623..29d631591a0fd 100644
--- a/llvm/test/Transforms/ConstraintElimination/ssub-with-overflow.ll
+++ b/llvm/test/Transforms/ConstraintElimination/ssub-with-overflow.ll
@@ -39,6 +39,46 @@ exit.fail:
   ret i8 0
 }
 
+declare void @use_res({ i8, i1 })
+
+define i8 @ssub_no_overflow_due_to_or_conds_result_used(i8 %a, i8 %b) {
+; CHECK-LABEL: @ssub_no_overflow_due_to_or_conds_result_used(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[C_1:%.*]] = icmp sle i8 [[B:%.*]], [[A:%.*]]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp slt i8 [[A]], 0
+; CHECK-NEXT:    [[OR_COND:%.*]] = or i1 [[C_2]], [[C_1]]
+; CHECK-NEXT:    br i1 [[OR_COND]], label [[EXIT_FAIL:%.*]], label [[MATH:%.*]]
+; CHECK:       math:
+; CHECK-NEXT:    [[OP:%.*]] = tail call { i8, i1 } @llvm.ssub.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 sle i8 %b, %a
+  %c.2 = icmp slt i8 %a, 0
+  %or.cond = or i1 %c.2, %c.1
+  br i1 %or.cond, label %exit.fail, label %math
+
+math:
+  %op = tail call { i8, i1 } @llvm.ssub.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 @ssub_no_overflow_due_to_and_conds(i8 %a, i8 %b) {
 ; CHECK-LABEL: @ssub_no_overflow_due_to_and_conds(
 ; CHECK-NEXT:  entry:
@@ -75,6 +115,40 @@ exit.fail:
   ret i8 0
 }
 
+define i8 @ssub_no_overflow_due_to_and_conds_sub_result_not_used(i8 %a, i8 %b) {
+; CHECK-LABEL: @ssub_no_overflow_due_to_and_conds_sub_result_not_used(
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[C_1:%.*]] = icmp sge i8 [[B:%.*]], [[A:%.*]]
+; CHECK-NEXT:    [[C_2:%.*]] = icmp sge i8 [[A]], 0
+; 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.ssub.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 sge i8 %b, %a
+  %c.2 = icmp sge i8 %a, 0
+  %and = and i1 %c.2, %c.1
+  br i1 %and, label %math, label %exit.fail
+
+math:
+  %op = tail call { i8, i1 } @llvm.ssub.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 @ssub_may_overflow1(i8 %a, i8 %b) {
 ; CHECK-LABEL: @ssub_may_overflow1(
 ; CHECK-NEXT:  entry: