Two changes relevant to LEA and x32:

[oota-llvm.git] / lib / Target / X86 / X86Schedule.td

diff --git a/lib/Target/X86/X86Schedule.td b/lib/Target/X86/X86Schedule.td
index dc311b15de3ade59e97bec4c50acb7cdde58c1d6..d99d085298f159c44a428b359f17ac77e897896a 100644 (file)
--- a/lib/Target/X86/X86Schedule.td
+++ b/lib/Target/X86/X86Schedule.td
@@ -8,7 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 //===----------------------------------------------------------------------===//
-// Instruction Itinerary classes used for X86 
+// Instruction Itinerary classes used for X86
 def IIC_DEFAULT     : InstrItinClass;
 def IIC_ALU_MEM     : InstrItinClass;
 def IIC_ALU_NONMEM  : InstrItinClass;
@@ -456,9 +456,31 @@ def IIC_NOP : InstrItinClass;
 //===----------------------------------------------------------------------===//
 // Processor instruction itineraries.
 
-def GenericItineraries : ProcessorItineraries<[], [], []>;
+// IssueWidth is analagous to the number of decode units. Core and its
+// descendents, including Nehalem and SandyBridge have 4 decoders.
+// Resources beyond the decoder operate on micro-ops and are bufferred
+// so adjacent micro-ops don't directly compete.
+//
+// MinLatency=0 indicates that RAW dependencies can be decoded in the
+// same cycle.
+//
+// HighLatency=10 is optimistic. X86InstrInfo::isHighLatencyDef
+// indicates high latency opcodes. Alternatively, InstrItinData
+// entries may be included here to define specific operand
+// latencies. Since these latencies are not used for pipeline hazards,
+// they do not need to be exact.
+//
+// ILPWindow=10 is an arbitrary threshold that approximates cycles of
+// latency hidden by instruction buffers. The actual value is not very
+// important but should be zero for inorder and nonzero for OOO processors.
+//
+// The GenericModel contains no instruciton itineraries.
+def GenericModel : SchedMachineModel {
+  let IssueWidth = 4;
+  let MinLatency = 0;
+  let LoadLatency = 4;
+  let HighLatency = 10;
+  let ILPWindow = 10;
+}
 
 include "X86ScheduleAtom.td"
-
-
-