Index: lib/Target/X86/X86InstrExtension.td
===================================================================
--- lib/Target/X86/X86InstrExtension.td
+++ lib/Target/X86/X86InstrExtension.td
@@ -12,32 +12,30 @@
 //===----------------------------------------------------------------------===//
 
 let hasSideEffects = 0 in {
-  let Defs = [AX], Uses = [AL] in
+  let Defs = [AX], Uses = [AL] in // AX = signext(AL)
   def CBW : I<0x98, RawFrm, (outs), (ins),
-              "{cbtw|cbw}", [], IIC_CBW>, OpSize16;  // AX = signext(AL)
-  let Defs = [EAX], Uses = [AX] in
+              "{cbtw|cbw}", [], IIC_CBW>, OpSize16, Sched<[WriteALU]>;
+  let Defs = [EAX], Uses = [AX] in // EAX = signext(AX)
   def CWDE : I<0x98, RawFrm, (outs), (ins),
-              "{cwtl|cwde}", [], IIC_CBW>, OpSize32; // EAX = signext(AX)
+              "{cwtl|cwde}", [], IIC_CBW>, OpSize32, Sched<[WriteALU]>;
 
-  let Defs = [AX,DX], Uses = [AX] in
+  let Defs = [AX,DX], Uses = [AX] in // DX:AX = signext(AX)
   def CWD : I<0x99, RawFrm, (outs), (ins),
-              "{cwtd|cwd}", [], IIC_CBW>, OpSize16; // DX:AX = signext(AX)
-  let Defs = [EAX,EDX], Uses = [EAX] in
+              "{cwtd|cwd}", [], IIC_CBW>, OpSize16, Sched<[WriteALU]>;
+  let Defs = [EAX,EDX], Uses = [EAX] in // EDX:EAX = signext(EAX)
   def CDQ : I<0x99, RawFrm, (outs), (ins),
-              "{cltd|cdq}", [], IIC_CBW>, OpSize32; // EDX:EAX = signext(EAX)
+              "{cltd|cdq}", [], IIC_CBW>, OpSize32, Sched<[WriteALU]>;
 
 
-  let Defs = [RAX], Uses = [EAX] in
+  let Defs = [RAX], Uses = [EAX] in // RAX = signext(EAX)
   def CDQE : RI<0x98, RawFrm, (outs), (ins),
-               "{cltq|cdqe}", [], IIC_CBW>;     // RAX = signext(EAX)
+               "{cltq|cdqe}", [], IIC_CBW>, Sched<[WriteALU]>;
 
-  let Defs = [RAX,RDX], Uses = [RAX] in
+  let Defs = [RAX,RDX], Uses = [RAX] in // RDX:RAX = signext(RAX)
   def CQO  : RI<0x99, RawFrm, (outs), (ins),
-                "{cqto|cqo}", [], IIC_CBW>; // RDX:RAX = signext(RAX)
+                "{cqto|cqo}", [], IIC_CBW>, Sched<[WriteALU]>;
 }
 
-
-
 // Sign/Zero extenders
 let hasSideEffects = 0 in {
 def MOVSX16rr8 : I<0xBE, MRMSrcReg, (outs GR16:$dst), (ins GR8:$src),
Index: lib/Target/X86/X86SchedSandyBridge.td
===================================================================
--- lib/Target/X86/X86SchedSandyBridge.td
+++ lib/Target/X86/X86SchedSandyBridge.td
@@ -865,6 +865,7 @@
   let NumMicroOps = 2;
   let ResourceCycles = [1,1];
 }
+def: InstRW<[SBWriteResGroup15], (instregex "CWD")>;
 def: InstRW<[SBWriteResGroup15], (instregex "FNSTSW16r")>;
 
 def SBWriteResGroup16 : SchedWriteRes<[SBPort1,SBPort05]> {
Index: test/CodeGen/X86/schedule-x86_64.ll
===================================================================
--- test/CodeGen/X86/schedule-x86_64.ll
+++ test/CodeGen/X86/schedule-x86_64.ll
@@ -755,7 +755,7 @@
 ; GENERIC-NEXT:    cltd # sched: [1:0.50]
 ; GENERIC-NEXT:    cltq # sched: [1:0.50]
 ; GENERIC-NEXT:    cqto # sched: [1:0.50]
-; GENERIC-NEXT:    cwtd
+; GENERIC-NEXT:    cwtd # sched: [2:1.00]
 ; GENERIC-NEXT:    cwtl # sched: [1:0.33]
 ; GENERIC-NEXT:    #NO_APP
 ; GENERIC-NEXT:    retq # sched: [1:1.00]
@@ -775,12 +775,12 @@
 ; SLM-LABEL: test_cbw_cdq_cdqe_cqo_cwd_cwde:
 ; SLM:       # BB#0:
 ; SLM-NEXT:    #APP
-; SLM-NEXT:    cbtw
-; SLM-NEXT:    cltd
-; SLM-NEXT:    cltq
-; SLM-NEXT:    cqto
-; SLM-NEXT:    cwtd
-; SLM-NEXT:    cwtl
+; SLM-NEXT:    cbtw # sched: [1:0.50]
+; SLM-NEXT:    cltd # sched: [1:0.50]
+; SLM-NEXT:    cltq # sched: [1:0.50]
+; SLM-NEXT:    cqto # sched: [1:0.50]
+; SLM-NEXT:    cwtd # sched: [1:0.50]
+; SLM-NEXT:    cwtl # sched: [1:0.50]
 ; SLM-NEXT:    #NO_APP
 ; SLM-NEXT:    retq # sched: [4:1.00]
 ;
@@ -791,7 +791,7 @@
 ; SANDY-NEXT:    cltd # sched: [1:0.50]
 ; SANDY-NEXT:    cltq # sched: [1:0.50]
 ; SANDY-NEXT:    cqto # sched: [1:0.50]
-; SANDY-NEXT:    cwtd
+; SANDY-NEXT:    cwtd # sched: [2:1.00]
 ; SANDY-NEXT:    cwtl # sched: [1:0.33]
 ; SANDY-NEXT:    #NO_APP
 ; SANDY-NEXT:    retq # sched: [1:1.00]
@@ -847,24 +847,24 @@
 ; BTVER2-LABEL: test_cbw_cdq_cdqe_cqo_cwd_cwde:
 ; BTVER2:       # BB#0:
 ; BTVER2-NEXT:    #APP
-; BTVER2-NEXT:    cbtw
-; BTVER2-NEXT:    cltd
-; BTVER2-NEXT:    cltq
-; BTVER2-NEXT:    cqto
-; BTVER2-NEXT:    cwtd
-; BTVER2-NEXT:    cwtl
+; BTVER2-NEXT:    cbtw # sched: [1:0.50]
+; BTVER2-NEXT:    cltd # sched: [1:0.50]
+; BTVER2-NEXT:    cltq # sched: [1:0.50]
+; BTVER2-NEXT:    cqto # sched: [1:0.50]
+; BTVER2-NEXT:    cwtd # sched: [1:0.50]
+; BTVER2-NEXT:    cwtl # sched: [1:0.50]
 ; BTVER2-NEXT:    #NO_APP
 ; BTVER2-NEXT:    retq # sched: [4:1.00]
 ;
 ; ZNVER1-LABEL: test_cbw_cdq_cdqe_cqo_cwd_cwde:
 ; ZNVER1:       # BB#0:
 ; ZNVER1-NEXT:    #APP
-; ZNVER1-NEXT:    cbtw
-; ZNVER1-NEXT:    cltd
-; ZNVER1-NEXT:    cltq
-; ZNVER1-NEXT:    cqto
-; ZNVER1-NEXT:    cwtd
-; ZNVER1-NEXT:    cwtl
+; ZNVER1-NEXT:    cbtw # sched: [1:0.25]
+; ZNVER1-NEXT:    cltd # sched: [1:0.25]
+; ZNVER1-NEXT:    cltq # sched: [1:0.25]
+; ZNVER1-NEXT:    cqto # sched: [1:0.25]
+; ZNVER1-NEXT:    cwtd # sched: [1:0.25]
+; ZNVER1-NEXT:    cwtl # sched: [1:0.25]
 ; ZNVER1-NEXT:    #NO_APP
 ; ZNVER1-NEXT:    retq # sched: [1:0.50]
   tail call void asm "cbw \0A\09 cdq \0A\09 cdqe \0A\09 cqo \0A\09 cwd \0A\09 cwde", ""() nounwind