[llvm-mca] Add command line option -call-latency (#92958)

Currently we assume a constant latency of 100 cycles for call
instructions. This commit allows the user to specify a custom value for
the same as a command line argument. Default latency is set to 100.

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/tools/llvm-mca/llvm-mca.cpp b/llvm/tools/llvm-mca/llvm-mca.cpp
index 03d7d79..cc5d4f5 100644
--- a/llvm/tools/llvm-mca/llvm-mca.cpp
+++ b/llvm/tools/llvm-mca/llvm-mca.cpp
@@ -135,6 +135,11 @@ static cl::opt<unsigned>
                                "(instructions per cycle)"),
                       cl::cat(ToolOptions), cl::init(0));
 
+static cl::opt<unsigned>
+    CallLatency("call-latency", cl::Hidden,
+                cl::desc("Number of cycles to assume for a call instruction"),
+                cl::cat(ToolOptions), cl::init(100U));
+
 enum class SkipType { NONE, LACK_SCHED, PARSE_FAILURE, ANY_FAILURE };
 
 static cl::opt<enum SkipType> SkipUnsupportedInstructions(
@@ -568,7 +573,7 @@ int main(int argc, char **argv) {
   }
 
   // Create an instruction builder.
-  mca::InstrBuilder IB(*STI, *MCII, *MRI, MCIA.get(), *IM);
+  mca::InstrBuilder IB(*STI, *MCII, *MRI, MCIA.get(), *IM, CallLatency);
 
   // Create a context to control ownership of the pipeline hardware.
   mca::Context MCA(*MRI, *STI);