[llvm] 6d2510d - [llvm-exegesis] Restrict to allowed back-to-back instructions in SerialSnippetGenerator.

[Clement Courbet via llvm-commits]

Author: Clement Courbet
Date: 2020-01-23T10:00:05+01:00
New Revision: 6d2510d30a01927546f115810fff82609c7ae9dd

URL: https://github.com/llvm/llvm-project/commit/6d2510d30a01927546f115810fff82609c7ae9dd
DIFF: https://github.com/llvm/llvm-project/commit/6d2510d30a01927546f115810fff82609c7ae9dd.diff

LOG: [llvm-exegesis] Restrict to allowed back-to-back instructions in SerialSnippetGenerator.

Summary: Followup to D73161.

Reviewers: gchatelet, mstojanovic

Subscribers: tschuett, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73256

Added: 
    

Modified: 
    llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp b/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp
index b0c881c4d62b..503c77c2ab6b 100644
--- a/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp
+++ b/llvm/tools/llvm-exegesis/lib/SerialSnippetGenerator.cpp
@@ -8,8 +8,9 @@
 
 #include "SerialSnippetGenerator.h"
 
-#include "MCInstrDescView.h"
 #include "CodeTemplate.h"
+#include "MCInstrDescView.h"
+#include "Target.h"
 #include <algorithm>
 #include <numeric>
 #include <vector>
@@ -50,6 +51,8 @@ computeAliasingInstructions(const LLVMState &State, const Instruction *Instr,
     const Instruction &OtherInstr = State.getIC().getInstr(OtherOpcode);
     if (OtherInstr.hasMemoryOperands())
       continue;
+    if (!State.getExegesisTarget().allowAsBackToBack(OtherInstr))
+      continue;
     if (Instr->hasAliasingRegistersThrough(OtherInstr, ForbiddenRegisters))
       AliasingInstructions.push_back(&OtherInstr);
     if (AliasingInstructions.size() >= MaxAliasingInstructions)