[MCA] Add flag -show-encoding to llvm-mca.
Flag -show-encoding enables the printing of instruction encodings as part of the
the instruction info view.
Example (with flags -mtriple=x86_64-- -mcpu=btver2):
Instruction Info:
[1]: #uOps
[2]: Latency
[3]: RThroughput
[4]: MayLoad
[5]: MayStore
[6]: HasSideEffects (U)
[7]: Encoding Size
[1] [2] [3] [4] [5] [6] [7] Encodings: Instructions:
1 2 1.00 4 c5 f0 59 d0 vmulps %xmm0, %xmm1, %xmm2
1 4 1.00 4 c5 eb 7c da vhaddps %xmm2, %xmm2, %xmm3
1 4 1.00 4 c5 e3 7c e3 vhaddps %xmm3, %xmm3, %xmm4
In this example, column Encoding Size is the size in bytes of the instruction
encoding. Column Encodings reports the actual instruction encodings as byte
sequences in hex (objdump style).
The computation of encodings is done by a utility class named mca::CodeEmitter.
In future, I plan to expose the CodeEmitter to the instruction builder, so that
information about instruction encoding sizes can be used by the simulator. That
would be a first step towards simulating the throughput from the decoders in the
hardware frontend.
Differential Revision: https://reviews.llvm.org/D65948
llvm-svn: 368432
diff --git a/llvm/tools/llvm-mca/Views/InstructionInfoView.cpp b/llvm/tools/llvm-mca/Views/InstructionInfoView.cpp
index 1fbffa3..a6f9153 100644
--- a/llvm/tools/llvm-mca/Views/InstructionInfoView.cpp
+++ b/llvm/tools/llvm-mca/Views/InstructionInfoView.cpp
@@ -12,6 +12,7 @@
//===----------------------------------------------------------------------===//
#include "Views/InstructionInfoView.h"
+#include "llvm/Support/FormattedStream.h"
namespace llvm {
namespace mca {
@@ -26,10 +27,17 @@
TempStream << "\n\nInstruction Info:\n";
TempStream << "[1]: #uOps\n[2]: Latency\n[3]: RThroughput\n"
- << "[4]: MayLoad\n[5]: MayStore\n[6]: HasSideEffects (U)\n\n";
+ << "[4]: MayLoad\n[5]: MayStore\n[6]: HasSideEffects (U)\n";
+ if (PrintEncodings) {
+ TempStream << "[7]: Encoding Size\n";
+ TempStream << "\n[1] [2] [3] [4] [5] [6] [7] "
+ << "Encodings: Instructions:\n";
+ } else {
+ TempStream << "\n[1] [2] [3] [4] [5] [6] Instructions:\n";
+ }
- TempStream << "[1] [2] [3] [4] [5] [6] Instructions:\n";
- for (const MCInst &Inst : Source) {
+ for (unsigned I = 0, E = Source.size(); I < E; ++I) {
+ const MCInst &Inst = Source[I];
const MCInstrDesc &MCDesc = MCII.get(Inst.getOpcode());
// Obtain the scheduling class information from the instruction.
@@ -72,7 +80,20 @@
}
TempStream << (MCDesc.mayLoad() ? " * " : " ");
TempStream << (MCDesc.mayStore() ? " * " : " ");
- TempStream << (MCDesc.hasUnmodeledSideEffects() ? " U " : " ");
+ TempStream << (MCDesc.hasUnmodeledSideEffects() ? " U " : " ");
+
+ if (PrintEncodings) {
+ StringRef Encoding(CE.getEncoding(I));
+ unsigned EncodingSize = Encoding.size();
+ TempStream << " " << EncodingSize
+ << (EncodingSize < 10 ? " " : " ");
+ TempStream.flush();
+ formatted_raw_ostream FOS(TempStream);
+ for (unsigned i = 0, e = Encoding.size(); i != e; ++i)
+ FOS << format("%02x ", (uint8_t)Encoding[i]);
+ FOS.PadToColumn(30);
+ FOS.flush();
+ }
MCIP.printInst(&Inst, InstrStream, "", STI);
InstrStream.flush();
@@ -80,7 +101,7 @@
// Consume any tabs or spaces at the beginning of the string.
StringRef Str(Instruction);
Str = Str.ltrim();
- TempStream << " " << Str << '\n';
+ TempStream << Str << '\n';
Instruction = "";
}