Re-commit : [PowerPC] Add handling for ColdCC calling convention and a pass to mark
candidates with coldcc attribute.
This recommits r322721 reverted due to sanitizer memory leak build bot failures.
Original commit message:
This patch adds support for the coldcc calling convention for Power.
This changes the set of non-volatile registers. It includes a pass to stress
test the implementation by marking all static directly called functions with
the coldcc attribute through the option -enable-coldcc-stress-test. It also
includes an option, -ppc-enable-coldcc, to add the coldcc attribute to
functions which are cold at all call sites based on BlockFrequencyInfo when
the containing function does not call any non cold functions.
Differential Revision: https://reviews.llvm.org/D38413
llvm-svn: 323778
diff --git a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
index aa4073f..226c75f 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
@@ -27,6 +27,11 @@
CacheLineSize("ppc-loop-prefetch-cache-line", cl::Hidden, cl::init(64),
cl::desc("The loop prefetch cache line size"));
+static cl::opt<bool>
+EnablePPCColdCC("ppc-enable-coldcc", cl::Hidden, cl::init(false),
+ cl::desc("Enable using coldcc calling conv for cold "
+ "internal functions"));
+
//===----------------------------------------------------------------------===//
//
// PPC cost model.
@@ -215,6 +220,14 @@
BaseT::getUnrollingPreferences(L, SE, UP);
}
+// This function returns true to allow using coldcc calling convention.
+// Returning true results in coldcc being used for functions which are cold at
+// all call sites when the callers of the functions are not calling any other
+// non coldcc functions.
+bool PPCTTIImpl::useColdCCForColdCall(Function &F) {
+ return EnablePPCColdCC;
+}
+
bool PPCTTIImpl::enableAggressiveInterleaving(bool LoopHasReductions) {
// On the A2, always unroll aggressively. For QPX unaligned loads, we depend
// on combining the loads generated for consecutive accesses, and failure to