[PowerPC] Add Branch Hints for Highly-Biased Branches
This branch adds hints for highly biased branches on the PPC architecture. Even
in absence of profiling information, LLVM will mark code reaching unreachable
terminators and other exceptional control flow constructs as highly unlikely to
be reached.
Patch by Tom Jablin!
llvm-svn: 255398
diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
index 6075631..acea600 100644
--- a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
+++ b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
@@ -56,6 +56,14 @@
PRED_BIT_UNSET = 1025
};
+ // Bit for branch taken (plus) or not-taken (minus) hint
+ enum BranchHintBit {
+ BR_NO_HINT = 0x0,
+ BR_NONTAKEN_HINT = 0x2,
+ BR_TAKEN_HINT = 0x3,
+ BR_HINT_MASK = 0X3
+ };
+
/// Invert the specified predicate. != -> ==, < -> >=.
Predicate InvertPredicate(Predicate Opcode);