Index: lib/Target/AArch64/AArch64SchedA57.td
===================================================================
--- lib/Target/AArch64/AArch64SchedA57.td
+++ lib/Target/AArch64/AArch64SchedA57.td
@@ -92,7 +92,7 @@
 def : SchedAlias<WriteFCopy, A57Write_5cyc_1L>;
 def : SchedAlias<WriteFImm,  A57Write_3cyc_1V>;
 def : SchedAlias<WriteFMul,  A57Write_5cyc_1V>;
-def : SchedAlias<WriteFDiv,  A57Write_18cyc_1X>;
+def : SchedAlias<WriteFDiv,  A57Write_17cyc_1W>;
 def : SchedAlias<WriteV,     A57Write_3cyc_1V>;
 def : SchedAlias<WriteVLD,   A57Write_5cyc_1L>;
 def : SchedAlias<WriteVST,   A57Write_1cyc_1S>;
@@ -444,19 +444,19 @@
 def : InstRW<[A57Write_5cyc_2V], (instregex "^[FVSU]CVT([AMNPZ][SU])?(_Int)?(v4f32|v2f64|v4i32|v2i64)")>;
 
 // ASIMD FP divide, D-form, F32
-def : InstRW<[A57Write_18cyc_1X], (instregex "FDIVv2f32")>;
+def : InstRW<[A57Write_17cyc_1W], (instregex "FDIVv2f32")>;
 // ASIMD FP divide, Q-form, F32
-def : InstRW<[A57Write_36cyc_2X], (instregex "FDIVv4f32")>;
+def : InstRW<[A57Write_34cyc_2W], (instregex "FDIVv4f32")>;
 // ASIMD FP divide, Q-form, F64
-def : InstRW<[A57Write_64cyc_2X], (instregex "FDIVv2f64")>;
+def : InstRW<[A57Write_64cyc_2W], (instregex "FDIVv2f64")>;
 
 // Note: These were simply duplicated from ASIMD FDIV because of missing documentation
 // ASIMD FP square root, D-form, F32
-def : InstRW<[A57Write_18cyc_1X], (instregex "FSQRTv2f32")>;
+def : InstRW<[A57Write_17cyc_1W], (instregex "FSQRTv2f32")>;
 // ASIMD FP square root, Q-form, F32
-def : InstRW<[A57Write_36cyc_2X], (instregex "FSQRTv4f32")>;
+def : InstRW<[A57Write_34cyc_2W], (instregex "FSQRTv4f32")>;
 // ASIMD FP square root, Q-form, F64
-def : InstRW<[A57Write_64cyc_2X], (instregex "FSQRTv2f64")>;
+def : InstRW<[A57Write_64cyc_2W], (instregex "FSQRTv2f64")>;
 
 // ASIMD FP max/min, normal, D-form
 def : InstRW<[A57Write_5cyc_1V], (instregex "^(FMAX|FMIN)(NM)?(v2f32)")>;
@@ -551,15 +551,15 @@
 def : InstRW<[A57Write_10cyc_1L_1V], (instregex "^[FSU]CVT[AMNPZ][SU](_Int)?[SU]?[XW]?[DS]?[rds]i?")>;
 def : InstRW<[A57Write_10cyc_1L_1V], (instregex "^[SU]CVTF")>;
 
-def : InstRW<[A57Write_32cyc_1X], (instrs FDIVDrr)>;
-def : InstRW<[A57Write_18cyc_1X], (instrs FDIVSrr)>;
+def : InstRW<[A57Write_32cyc_1W], (instrs FDIVDrr)>;
+def : InstRW<[A57Write_17cyc_1W], (instrs FDIVSrr)>;
 
 def : InstRW<[A57Write_5cyc_1V], (instregex "^F(MAX|MIN).+rr")>;
 
 def : InstRW<[A57Write_5cyc_1V], (instregex "^FRINT.+r")>;
 
-def : InstRW<[A57Write_32cyc_1X], (instrs FSQRTDr)>;
-def : InstRW<[A57Write_18cyc_1X], (instrs FSQRTSr)>;
+def : InstRW<[A57Write_32cyc_1W], (instrs FSQRTDr)>;
+def : InstRW<[A57Write_17cyc_1W], (instrs FSQRTSr)>;
 
 def : InstRW<[A57Write_5cyc_1L, WriteLDHi], (instrs LDNPDi)>;
 def : InstRW<[A57Write_6cyc_2L, WriteLDHi], (instrs LDNPQi)>;
Index: lib/Target/AArch64/AArch64SchedA57WriteRes.td
===================================================================
--- lib/Target/AArch64/AArch64SchedA57WriteRes.td
+++ lib/Target/AArch64/AArch64SchedA57WriteRes.td
@@ -28,15 +28,15 @@
 def A57Write_5cyc_1V  : SchedWriteRes<[A57UnitV]> { let Latency = 5;  }
 def A57Write_5cyc_1W  : SchedWriteRes<[A57UnitW]> { let Latency = 5;  }
 def A57Write_10cyc_1V : SchedWriteRes<[A57UnitV]> { let Latency = 10; }
-def A57Write_18cyc_1X : SchedWriteRes<[A57UnitX]> { let Latency = 18;
-                                                    let ResourceCycles = [18]; }
+def A57Write_17cyc_1W : SchedWriteRes<[A57UnitW]> { let Latency = 17;
+                                                    let ResourceCycles = [17]; }
 def A57Write_19cyc_1M : SchedWriteRes<[A57UnitM]> { let Latency = 19;
                                                     let ResourceCycles = [19]; }
 def A57Write_1cyc_1B  : SchedWriteRes<[A57UnitB]> { let Latency = 1;  }
 def A57Write_1cyc_1I  : SchedWriteRes<[A57UnitI]> { let Latency = 1;  }
 def A57Write_1cyc_1S  : SchedWriteRes<[A57UnitS]> { let Latency = 1;  }
 def A57Write_2cyc_1M  : SchedWriteRes<[A57UnitM]> { let Latency = 2;  }
-def A57Write_32cyc_1X : SchedWriteRes<[A57UnitX]> { let Latency = 32;
+def A57Write_32cyc_1W : SchedWriteRes<[A57UnitW]> { let Latency = 32;
                                                     let ResourceCycles = [32]; }
 def A57Write_35cyc_1M : SchedWriteRes<[A57UnitM]> { let Latency = 35;
                                                     let ResourceCycles = [35]; }
@@ -54,7 +54,7 @@
 //===----------------------------------------------------------------------===//
 // Define Generic 2 micro-op types
 
-def A57Write_64cyc_2X    : SchedWriteRes<[A57UnitX, A57UnitX]> {
+def A57Write_64cyc_2W    : SchedWriteRes<[A57UnitW, A57UnitW]> {
   let Latency     = 64;
   let NumMicroOps = 2;
   let ResourceCycles = [32, 32];
@@ -139,10 +139,10 @@
   let Latency     = 2;
   let NumMicroOps = 2;
 }
-def A57Write_36cyc_2X    : SchedWriteRes<[A57UnitX, A57UnitX]> {
-  let Latency     = 36;
+def A57Write_34cyc_2W    : SchedWriteRes<[A57UnitW, A57UnitW]> {
+  let Latency     = 34;
   let NumMicroOps = 2;
-  let ResourceCycles = [18, 18];
+  let ResourceCycles = [17, 17];
 }
 def A57Write_3cyc_1I_1M  : SchedWriteRes<[A57UnitI,
                                           A57UnitM]> {
Index: test/CodeGen/AArch64/arm64-misched-A57-div-fix.ll
===================================================================
--- test/CodeGen/AArch64/arm64-misched-A57-div-fix.ll
+++ test/CodeGen/AArch64/arm64-misched-A57-div-fix.ll
@@ -0,0 +1,18 @@
+; REQUIRES: asserts
+;
+; FDIV/FSQRT should use A57UnitW, not A57UnitX
+;
+; RUN: llc < %s -mtriple=arm64-linux-gnu -mcpu=cortex-a57 -enable-misched -verify-misched -debug-only=misched -o - 2>&1 > /dev/null | FileCheck %s
+;
+; CHECK-NOT: A57UnitX
+; CHECK:      picking next node
+; CHECK:      FDIVSrr
+; CHECK:      Critical: [[NUM:[0-9]+]]c, [[NUM]] A57UnitW
+; CHECK-NEXT: ExpectedLatency: 18c
+
+define float @main(float %a, float %b) nounwind {
+entry:
+  %div = fdiv float %a, %b
+  ret float %div
+}
+