[PATCH] D24660: [Sparc][LEON] Erratum fix to replace broken SDIV instruction with SDIVcc.

[Chris Dewhurst via llvm-commits]

lero_chris updated this revision to Diff 73740.
lero_chris added a comment.

Indentation in new code caused by Tab usage fixed and replaced with spaces.


Repository:
  rL LLVM

https://reviews.llvm.org/D24660

Files:
  lib/Target/Sparc/LeonFeatures.td
  lib/Target/Sparc/Sparc.td
  lib/Target/Sparc/SparcISelDAGToDAG.cpp
  lib/Target/Sparc/SparcSubtarget.cpp
  lib/Target/Sparc/SparcSubtarget.h


Index: lib/Target/Sparc/SparcSubtarget.h
===================================================================
--- lib/Target/Sparc/SparcSubtarget.h
+++ lib/Target/Sparc/SparcSubtarget.h
@@ -48,6 +48,7 @@
   bool FixFSMULD;
   bool ReplaceFMULS;
   bool FixAllFDIVSQRT;
+  bool PerformSDIVReplace;
 
   SparcInstrInfo InstrInfo;
   SparcTargetLowering TLInfo;
@@ -86,6 +87,7 @@
 
   // Leon options
   bool hasUmacSmac() const { return HasUmacSmac; }
+  bool performSDIVReplace() const { return PerformSDIVReplace; }
   bool hasLeonCasa() const { return HasLeonCasa; }
   bool insertNOPLoad() const { return InsertNOPLoad; }
   bool fixFSMULD() const { return FixFSMULD; }
Index: lib/Target/Sparc/SparcSubtarget.cpp
===================================================================
--- lib/Target/Sparc/SparcSubtarget.cpp
+++ lib/Target/Sparc/SparcSubtarget.cpp
@@ -39,6 +39,7 @@
   // Leon features
   HasLeonCasa = false;
   HasUmacSmac = false;
+  PerformSDIVReplace = false;
   InsertNOPLoad = false;
   FixFSMULD = false;
   ReplaceFMULS = false;
Index: lib/Target/Sparc/SparcISelDAGToDAG.cpp
===================================================================
--- lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -360,6 +360,12 @@
 
     // FIXME: Handle div by immediate.
     unsigned Opcode = N->getOpcode() == ISD::SDIV ? SP::SDIVrr : SP::UDIVrr;
+    // SDIV is a hardware erratum on some LEON2 processors. Replace it with SDIVcc here.
+    if (((SparcTargetMachine&)TM).getSubtargetImpl()->performSDIVReplace()
+        &&
+        Opcode == SP::SDIVrr) {
+      Opcode = SP::SDIVCCrr;
+    }
     CurDAG->SelectNodeTo(N, Opcode, MVT::i32, DivLHS, DivRHS, TopPart);
     return;
   }
Index: lib/Target/Sparc/Sparc.td
===================================================================
--- lib/Target/Sparc/Sparc.td
+++ lib/Target/Sparc/Sparc.td
@@ -110,7 +110,7 @@
 // LEON 2 FT (AT697E)
 // TO DO: Place-holder: Processor specific features will be added *very* soon here.
 def : Processor<"at697e", LEON2Itineraries,
-                [FeatureLeon, InsertNOPLoad]>;
+                [FeatureLeon, ReplaceSDIV, InsertNOPLoad]>;
 
 // LEON 2 FT (AT697F)
 // TO DO: Place-holder: Processor specific features will be added *very* soon here.
Index: lib/Target/Sparc/LeonFeatures.td
===================================================================
--- lib/Target/Sparc/LeonFeatures.td
+++ lib/Target/Sparc/LeonFeatures.td
@@ -37,6 +37,14 @@
   "Enable CASA instruction for LEON3 and LEON4 processors"
 >;
 
+
+def ReplaceSDIV : SubtargetFeature<
+  "replacesdiv",
+  "PerformSDIVReplace",
+  "true",
+  "AT697E erratum fix: Do not emit SDIV, emit SDIVCC instead"
+>;
+          
 def InsertNOPLoad: SubtargetFeature<
   "insertnopload",
   "InsertNOPLoad",


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