[IPO] Avoid repeated hash lookups (NFC)

[kazutakahirata]

The two "if" conditions are mutually exclusive, so we can put them in
any order. Reversing the order allows us to remove
Blocks.contains(IncomingBlock) in one of the "if" conditions.

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Kazu Hirata (kazutakahirata)

Changes

The two "if" conditions are mutually exclusive, so we can put them in
any order. Reversing the order allows us to remove
Blocks.contains(IncomingBlock) in one of the "if" conditions.

---

Full diff: https://github.com/llvm/llvm-project/pull/125639.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/IPO/IROutliner.cpp (+6-6)

diff --git a/llvm/lib/Transforms/IPO/IROutliner.cpp b/llvm/lib/Transforms/IPO/IROutliner.cpp
index 41bc67f2b6891b..34ddeeb37400cf 100644
--- a/llvm/lib/Transforms/IPO/IROutliner.cpp
+++ b/llvm/lib/Transforms/IPO/IROutliner.cpp
@@ -1184,22 +1184,22 @@ static std::optional<unsigned> getGVNForPHINode(OutlinableRegion &Region,
   for (unsigned Idx = 0, EIdx = PN->getNumIncomingValues(); Idx < EIdx; Idx++) {
     Incoming = PN->getIncomingValue(Idx);
     IncomingBlock = PN->getIncomingBlock(Idx);
+    // If the incoming block isn't in the region, we don't have to worry about
+    // this incoming value.
+    if (!Blocks.contains(IncomingBlock))
+      continue;
+
     // If we cannot find a GVN, and the incoming block is included in the region
     // this means that the input to the PHINode is not included in the region we
     // are trying to analyze, meaning, that if it was outlined, we would be
     // adding an extra input.  We ignore this case for now, and so ignore the
     // region.
     std::optional<unsigned> OGVN = Cand.getGVN(Incoming);
-    if (!OGVN && Blocks.contains(IncomingBlock)) {
+    if (!OGVN) {
       Region.IgnoreRegion = true;
       return std::nullopt;
     }
 
-    // If the incoming block isn't in the region, we don't have to worry about
-    // this incoming value.
-    if (!Blocks.contains(IncomingBlock))
-      continue;
-
     // Collect the canonical numbers of the values in the PHINode.
     unsigned GVN = *OGVN;
     OGVN = Cand.getCanonicalNum(GVN);