[PATCH] D85343: [ConstraintElimination] Add support for Or.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.
fhahn requested review of this revision.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D85343

Files:
  llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
  llvm/test/Transforms/ConstraintElimination/or.ll


Index: llvm/test/Transforms/ConstraintElimination/or.ll
===================================================================
--- llvm/test/Transforms/ConstraintElimination/or.ll
+++ llvm/test/Transforms/ConstraintElimination/or.ll
@@ -18,15 +18,15 @@
 ; CHECK-NEXT:    ret i32 10
 ; CHECK:       exit:
 ; CHECK-NEXT:    [[F_1:%.*]] = icmp ule i32 [[X]], [[Z]]
-; CHECK-NEXT:    call void @use(i1 [[F_1]])
+; CHECK-NEXT:    call void @use(i1 false)
 ; CHECK-NEXT:    [[C_5:%.*]] = icmp ule i32 [[X]], [[A]]
 ; CHECK-NEXT:    call void @use(i1 [[C_5]])
 ; CHECK-NEXT:    [[T_1:%.*]] = icmp ugt i32 [[Y]], [[Z]]
-; CHECK-NEXT:    call void @use(i1 [[T_1]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    [[T_2:%.*]] = icmp ugt i32 [[X]], [[Y]]
-; CHECK-NEXT:    call void @use(i1 [[T_2]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    [[T_3:%.*]] = icmp ugt i32 [[X]], [[Z]]
-; CHECK-NEXT:    call void @use(i1 [[T_3]])
+; CHECK-NEXT:    call void @use(i1 true)
 ; CHECK-NEXT:    ret i32 20
 ;
 entry:
Index: llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
+++ llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
@@ -172,6 +172,18 @@
     auto *Br = dyn_cast<BranchInst>(BB.getTerminator());
     if (!Br || !Br->isConditional())
       continue;
+
+    if (match(Br->getCondition(), m_Or(m_Cmp(), m_Cmp()))) {
+      if (Br->getSuccessor(1)->getSinglePredecessor()) {
+        auto *OrI = cast<Instruction>(Br->getCondition());
+        WorkList.emplace_back(DT.getNode(Br->getSuccessor(1)),
+                              cast<CmpInst>(OrI->getOperand(0)), true);
+        WorkList.emplace_back(DT.getNode(Br->getSuccessor(1)),
+                              cast<CmpInst>(OrI->getOperand(1)), true);
+      }
+      continue;
+    }
+
     auto *CmpI = dyn_cast<CmpInst>(Br->getCondition());
     if (!CmpI)
       continue;


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