[PATCH] D22082: LiveRegUnits: Add accumulateBackward() function

[Quentin Colombet via llvm-commits]

qcolombet accepted this revision.
This revision is now accepted and ready to land.

================
Comment at: include/llvm/CodeGen/LiveRegUnits.h:81
@@ +80,3 @@
+  /// The regmask has the same format as the one in the RegMask machine operand.
+  void addRegsInMask(const uint32_t *RegMask);
+
----------------
Rename into addRegsNotPreservedByMask.

================
Comment at: lib/CodeGen/RegisterScavenging.cpp:358
@@ -357,1 +357,3 @@
 
+/// Searches backwards for a register usable between \p From and \To.
+/// - If there exists a free register that is not part of \p LiveOut, then
----------------
\p To

================
Comment at: lib/CodeGen/RegisterScavenging.cpp:571
@@ +570,3 @@
+  if (Reg == 0) {
+    llvm_unreachable("No register left to scavenge!");
+  } else if (MBB.end() == SpillAfter) {
----------------
You didn’t like the assert :P.

================
Comment at: lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp:507
@@ +506,3 @@
+    Units.stepBackward(*I);
+  } while (I != ChainEnd);
+
----------------
That would be weird, but, to be safe, shouldn’t we do the test before the call to stepBackward, i.e., if MBB is empty that will crash, right?


Repository:
  rL LLVM

https://reviews.llvm.org/D22082