[RISCV] Collect Statistics on Compressed Instructions

Summary:
It is useful to keep statistics on how many instructions we have
compressed, so we can see if future changes are increasing or decreasing this
number.

Reviewers: asb, luismarques

Reviewed By: asb, luismarques

Subscribers: xbolva00, sameer.abuasal, hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, pzheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67495

1 files changed, 6 insertions, 0 deletions

diff --git a/llvm/lib/Target/RISCV/RISCVAsmPrinter.cpp b/llvm/lib/Target/RISCV/RISCVAsmPrinter.cpp
index 57631dcb511..7247adf4884 100644
--- a/llvm/lib/Target/RISCV/RISCVAsmPrinter.cpp
+++ b/llvm/lib/Target/RISCV/RISCVAsmPrinter.cpp
@@ -16,6 +16,7 @@
 #include "MCTargetDesc/RISCVMCExpr.h"
 #include "RISCVTargetMachine.h"
 #include "TargetInfo/RISCVTargetInfo.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/MachineConstantPool.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
@@ -31,6 +32,9 @@ using namespace llvm;
 
 #define DEBUG_TYPE "asm-printer"
 
+STATISTIC(RISCVNumInstrsCompressed,
+          "Number of RISC-V Compressed instructions emitted");
+
 namespace {
 class RISCVAsmPrinter : public AsmPrinter {
 public:
@@ -64,6 +68,8 @@ void RISCVAsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
   MCInst CInst;
   bool Res = compressInst(CInst, Inst, *TM.getMCSubtargetInfo(),
                           OutStreamer->getContext());
+  if (Res)
+    ++RISCVNumInstrsCompressed;
   AsmPrinter::EmitToStreamer(*OutStreamer, Res ? CInst : Inst);
 }