1 files changed, 18 insertions, 3 deletions
diff --git a/llvm/lib/Target/X86/X86.td b/llvm/lib/Target/X86/X86.td
index 2c064c43d9d..9f0d8aa0d35 100644
--- a/llvm/lib/Target/X86/X86.td
+++ b/llvm/lib/Target/X86/X86.td
@@ -305,8 +305,16 @@ def FeatureFastLZCNT
     : SubtargetFeature<
           "fast-lzcnt", "HasFastLZCNT", "true",
           "LZCNT instructions are as fast as most simple integer ops">;
-
-
+// If the target can efficiently decode NOPs upto 11-bytes in length.
+def FeatureFast11ByteNOP
+    : SubtargetFeature<
+          "fast-11bytenop", "HasFast11ByteNOP", "true",
+          "Target can quickly decode up to 11 byte NOPs">;
+// If the target can efficiently decode NOPs upto 15-bytes in length.
+def FeatureFast15ByteNOP
+    : SubtargetFeature<
+          "fast-15bytenop", "HasFast15ByteNOP", "true",
+          "Target can quickly decode up to 15 byte NOPs">;
 // Sandy Bridge and newer processors can use SHLD with the same source on both
 // inputs to implement rotate to avoid the partial flag update of the normal
 // rotate instructions.
@@ -849,7 +857,8 @@ def : Proc<"btver1", [
   FeatureLZCNT,
   FeaturePOPCNT,
   FeatureSlowSHLD,
-  FeatureLAHFSAHF
+  FeatureLAHFSAHF,
+  FeatureFast15ByteNOP
 ]>;
 
 // Jaguar
@@ -874,6 +883,7 @@ def : ProcessorModel<"btver2", BtVer2Model, [
   FeatureXSAVEOPT,
   FeatureSlowSHLD,
   FeatureLAHFSAHF,
+  FeatureFast15ByteNOP,
   FeatureFastPartialYMMorZMMWrite
 ]>;
 
@@ -897,6 +907,7 @@ def : Proc<"bdver1", [
   FeatureLWP,
   FeatureSlowSHLD,
   FeatureLAHFSAHF,
+  FeatureFast11ByteNOP,
   FeatureMacroFusion
 ]>;
 // Piledriver
@@ -923,6 +934,7 @@ def : Proc<"bdver2", [
   FeatureFMA,
   FeatureSlowSHLD,
   FeatureLAHFSAHF,
+  FeatureFast11ByteNOP,
   FeatureMacroFusion
 ]>;
 
@@ -952,6 +964,7 @@ def : Proc<"bdver3", [
   FeatureSlowSHLD,
   FeatureFSGSBase,
   FeatureLAHFSAHF,
+  FeatureFast11ByteNOP,
   FeatureMacroFusion
 ]>;
 
@@ -981,6 +994,7 @@ def : Proc<"bdver4", [
   FeatureSlowSHLD,
   FeatureFSGSBase,
   FeatureLAHFSAHF,
+  FeatureFast11ByteNOP,
   FeatureMWAITX,
   FeatureMacroFusion
 ]>;
@@ -1003,6 +1017,7 @@ def: ProcessorModel<"znver1", Znver1Model, [
   FeatureFastLZCNT,
   FeatureLAHFSAHF,
   FeatureLZCNT,
+  FeatureFast15ByteNOP,
   FeatureMacroFusion,
   FeatureMMX,
   FeatureMOVBE,