[LICM] Avoid repeating expensive call while promoting loads. NFC

[anna]

Summary

We can avoid repeating the check isGuaranteedToExecute when it's already called once while checking if the alignment can be widened for the load/store being hoisted.

The function is invariant for the same instruction UI in isGuaranteedToExecute(*UI, DT, CurLoop, SafetyInfo);

[eli.friedman]

Nit: in an if-else if, please use braces consistently.

Otherwise LGTM.

llvm/trunk/lib/Transforms/Scalar/LICM.cpp

for (User *U : ASIV->users()) {
         // so that we do not introduce stores where they did not exist before
         // (which would break the LLVM concurrency model).
 
         // If the alignment of this instruction allows us to specify a more
         // restrictive (and performant) alignment and if we are sure this
         // instruction will be executed, update the alignment.
         // Larger is better, with the exception of 0 being the best alignment.
         unsigned InstAlignment = Store->getAlignment();
-        if ((InstAlignment > Alignment || InstAlignment == 0) && Alignment != 0)
+        if ((InstAlignment > Alignment || InstAlignment == 0) &&
+            Alignment != 0) {
           if (isGuaranteedToExecute(*UI, DT, CurLoop, SafetyInfo)) {
             GuaranteedToExecute = true;
             Alignment = InstAlignment;
           }
-
-        if (!GuaranteedToExecute)
+        } else if (!GuaranteedToExecute) {
           GuaranteedToExecute =
               isGuaranteedToExecute(*UI, DT, CurLoop, SafetyInfo);
+        }
 
         if (!GuaranteedToExecute && !CanSpeculateLoad) {
           CanSpeculateLoad = isDereferenceableAndAlignedPointer(
               Store->getPointerOperand(), Store->getAlignment(), MDL,
               Preheader->getTerminator(), DT, TLI);
         }
       } else
         return Changed; // Not a load or store.