From 8293f7434577e23a07284686f5b54079e22e6a91 Mon Sep 17 00:00:00 2001
From: Philip Reames <listmail@philipreames.com>
Date: Thu, 21 Nov 2019 15:06:01 -0800
Subject: Further cleanup manipulation of widenable branches [NFC]

This is a follow on to aaea24802bf5.  In post commit discussion, Artur and I realized we could cleanup the code using Uses; this patch does so.
---
 llvm/lib/Transforms/Utils/GuardUtils.cpp | 40 ++++++++++++++------------------
 1 file changed, 18 insertions(+), 22 deletions(-)

(limited to 'llvm/lib/Transforms/Utils/GuardUtils.cpp')

diff --git a/llvm/lib/Transforms/Utils/GuardUtils.cpp b/llvm/lib/Transforms/Utils/GuardUtils.cpp
index 241bfbf80bd..4cfc9358499 100644
--- a/llvm/lib/Transforms/Utils/GuardUtils.cpp
+++ b/llvm/lib/Transforms/Utils/GuardUtils.cpp
@@ -87,23 +87,20 @@ void llvm::widenWidenableBranch(BranchInst *WidenableBR, Value *NewCond) {
   // condition, but that doesn't match the pattern parseWidenableBranch expects
   // so we have to be more sophisticated.
 
-  if (match(WidenableBR->getCondition(),
-            m_Intrinsic<Intrinsic::experimental_widenable_condition>())) {
+  Use *C, *WC;
+  BasicBlock *IfTrueBB, *IfFalseBB;
+  parseWidenableBranch(WidenableBR, C, WC, IfTrueBB, IfFalseBB);
+  if (!C) {
+    // br (wc()), ... form
     IRBuilder<> B(WidenableBR);
-    WidenableBR->setCondition(B.CreateAnd(NewCond,
-                                          WidenableBR->getCondition()));
+    WidenableBR->setCondition(B.CreateAnd(NewCond, WC->get()));
   } else {
+    // br (wc & C), ... form
+    IRBuilder<> B(WidenableBR);
+    C->set(B.CreateAnd(NewCond, C->get()));
     Instruction *WCAnd = cast<Instruction>(WidenableBR->getCondition());
     // Condition is only guaranteed to dominate branch
-    WCAnd->moveBefore(WidenableBR);
-    IRBuilder<> B(WCAnd);
-    const bool Op0IsWC =
-      match(WCAnd->getOperand(0),
-            m_Intrinsic<Intrinsic::experimental_widenable_condition>());
-    const unsigned CondOpIdx = Op0IsWC ? 1 : 0;
-    Value *OldCond = WCAnd->getOperand(CondOpIdx);
-    NewCond = B.CreateAnd(NewCond, OldCond);
-    WCAnd->setOperand(CondOpIdx, NewCond);
+    WCAnd->moveBefore(WidenableBR);    
   }
   assert(isWidenableBranch(WidenableBR) && "preserve widenabiliy");
 }
@@ -111,20 +108,19 @@ void llvm::widenWidenableBranch(BranchInst *WidenableBR, Value *NewCond) {
 void llvm::setWidenableBranchCond(BranchInst *WidenableBR, Value *NewCond) {
   assert(isWidenableBranch(WidenableBR) && "precondition");
 
-  if (match(WidenableBR->getCondition(),
-            m_Intrinsic<Intrinsic::experimental_widenable_condition>())) {
+  Use *C, *WC;
+  BasicBlock *IfTrueBB, *IfFalseBB;
+  parseWidenableBranch(WidenableBR, C, WC, IfTrueBB, IfFalseBB);
+  if (!C) {
+    // br (wc()), ... form
     IRBuilder<> B(WidenableBR);
-    WidenableBR->setCondition(B.CreateAnd(NewCond,
-                                          WidenableBR->getCondition()));
+    WidenableBR->setCondition(B.CreateAnd(NewCond, WC->get()));
   } else {
+    // br (wc & C), ... form
     Instruction *WCAnd = cast<Instruction>(WidenableBR->getCondition());
     // Condition is only guaranteed to dominate branch
     WCAnd->moveBefore(WidenableBR);
-    const bool Op0IsWC =
-      match(WCAnd->getOperand(0),
-            m_Intrinsic<Intrinsic::experimental_widenable_condition>());
-    const unsigned CondOpIdx = Op0IsWC ? 1 : 0;
-    WCAnd->setOperand(CondOpIdx, NewCond);
+    C->set(NewCond);
   }
   assert(isWidenableBranch(WidenableBR) && "preserve widenabiliy");
 }
-- 
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