Index: lib/Target/X86/X86TargetMachine.cpp
===================================================================
--- lib/Target/X86/X86TargetMachine.cpp
+++ lib/Target/X86/X86TargetMachine.cpp
@@ -109,12 +109,15 @@
   if (Subtarget.isTargetWin64())
     this->Options.TrapUnreachable = true;
 
-  // TODO: By default, all reciprocal estimate operations are off because
-  // that matches the behavior before TargetRecip was added (except for btver2
-  // which used subtarget features to enable this type of codegen).
-  // We should change this to match GCC behavior where everything but
-  // scalar division estimates are turned on by default with -ffast-math.
-  this->Options.Reciprocals.setDefaults("all", false, 1);
+  // By default (and when -ffast-math is on), enable estimate codegen for
+  // everything except scalar division. By default, use 1 refinement step for
+  // all operations. Defaults may be overridden by using command-line options.
+  // Scalar division estimates are disabled because they break too much
+  // real-world code. These defaults match GCC behavior.
+  this->Options.Reciprocals.setDefaults("sqrtf", true, 1);
+  this->Options.Reciprocals.setDefaults("divf", false, 1);
+  this->Options.Reciprocals.setDefaults("vec-sqrtf", true, 1);
+  this->Options.Reciprocals.setDefaults("vec-divf", true, 1);
 
   initAsmInfo();
 }
Index: test/CodeGen/X86/recip-fastmath.ll
===================================================================
--- test/CodeGen/X86/recip-fastmath.ll
+++ test/CodeGen/X86/recip-fastmath.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=sse2 | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=sse2 -recip=!divf,!vec-divf | FileCheck %s --check-prefix=NORECIP
 ; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx -recip=divf,vec-divf | FileCheck %s --check-prefix=RECIP
 ; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx -recip=divf:2,vec-divf:2 | FileCheck %s --check-prefix=REFINE
 
@@ -14,11 +14,11 @@
   %div = fdiv fast float 1.0, %x
   ret float %div
 
-; CHECK-LABEL: reciprocal_estimate:
-; CHECK: movss
-; CHECK-NEXT: divss
-; CHECK-NEXT: movaps
-; CHECK-NEXT: retq
+; NORECIP-LABEL: reciprocal_estimate:
+; NORECIP: movss
+; NORECIP-NEXT: divss
+; NORECIP-NEXT: movaps
+; NORECIP-NEXT: retq
 
 ; RECIP-LABEL: reciprocal_estimate:
 ; RECIP: vrcpss
@@ -45,11 +45,11 @@
   %div = fdiv fast <4 x float> <float 1.0, float 1.0, float 1.0, float 1.0>, %x
   ret <4 x float> %div
 
-; CHECK-LABEL: reciprocal_estimate_v4f32:
-; CHECK: movaps
-; CHECK-NEXT: divps
-; CHECK-NEXT: movaps
-; CHECK-NEXT: retq
+; NORECIP-LABEL: reciprocal_estimate_v4f32:
+; NORECIP: movaps
+; NORECIP-NEXT: divps
+; NORECIP-NEXT: movaps
+; NORECIP-NEXT: retq
 
 ; RECIP-LABEL: reciprocal_estimate_v4f32:
 ; RECIP: vrcpps
@@ -76,14 +76,14 @@
   %div = fdiv fast <8 x float> <float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0, float 1.0>, %x
   ret <8 x float> %div
 
-; CHECK-LABEL: reciprocal_estimate_v8f32:
-; CHECK: movaps
-; CHECK: movaps
-; CHECK-NEXT: divps
-; CHECK-NEXT: divps
-; CHECK-NEXT: movaps
-; CHECK-NEXT: movaps
-; CHECK-NEXT: retq
+; NORECIP-LABEL: reciprocal_estimate_v8f32:
+; NORECIP: movaps
+; NORECIP: movaps
+; NORECIP-NEXT: divps
+; NORECIP-NEXT: divps
+; NORECIP-NEXT: movaps
+; NORECIP-NEXT: movaps
+; NORECIP-NEXT: retq
 
 ; RECIP-LABEL: reciprocal_estimate_v8f32:
 ; RECIP: vrcpps
Index: test/CodeGen/X86/sqrt-fastmath.ll
===================================================================
--- test/CodeGen/X86/sqrt-fastmath.ll
+++ test/CodeGen/X86/sqrt-fastmath.ll
@@ -1,4 +1,4 @@
-; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=sse2 | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=sse2 -recip=!sqrtf,!vec-sqrtf,!divf,!vec-divf | FileCheck %s --check-prefix=NORECIP
 ; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx -recip=sqrtf,vec-sqrtf | FileCheck %s --check-prefix=ESTIMATE
 
 declare double @__sqrt_finite(double) #0
@@ -10,10 +10,10 @@
 
 
 define double @fd(double %d) #0 {
-; CHECK-LABEL: fd:
-; CHECK:       # BB#0:
-; CHECK-NEXT:    sqrtsd %xmm0, %xmm0
-; CHECK-NEXT:    retq
+; NORECIP-LABEL: fd:
+; NORECIP:       # BB#0:
+; NORECIP-NEXT:    sqrtsd %xmm0, %xmm0
+; NORECIP-NEXT:    retq
 ;
 ; ESTIMATE-LABEL: fd:
 ; ESTIMATE:       # BB#0:
@@ -25,10 +25,10 @@
 
 
 define float @ff(float %f) #0 {
-; CHECK-LABEL: ff:
-; CHECK:       # BB#0:
-; CHECK-NEXT:    sqrtss %xmm0, %xmm0
-; CHECK-NEXT:    retq
+; NORECIP-LABEL: ff:
+; NORECIP:       # BB#0:
+; NORECIP-NEXT:    sqrtss %xmm0, %xmm0
+; NORECIP-NEXT:    retq
 ;
 ; ESTIMATE-LABEL: ff:
 ; ESTIMATE:       # BB#0:
@@ -49,11 +49,11 @@
 
 
 define x86_fp80 @fld(x86_fp80 %ld) #0 {
-; CHECK-LABEL: fld:
-; CHECK:       # BB#0:
-; CHECK-NEXT:    fldt {{[0-9]+}}(%rsp)
-; CHECK-NEXT:    fsqrt
-; CHECK-NEXT:    retq
+; NORECIP-LABEL: fld:
+; NORECIP:       # BB#0:
+; NORECIP-NEXT:    fldt {{[0-9]+}}(%rsp)
+; NORECIP-NEXT:    fsqrt
+; NORECIP-NEXT:    retq
 ;
 ; ESTIMATE-LABEL: fld:
 ; ESTIMATE:       # BB#0:
@@ -67,12 +67,12 @@
 
 
 define float @reciprocal_square_root(float %x) #0 {
-; CHECK-LABEL: reciprocal_square_root:
-; CHECK:       # BB#0:
-; CHECK-NEXT:    sqrtss %xmm0, %xmm1
-; CHECK-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
-; CHECK-NEXT:    divss %xmm1, %xmm0
-; CHECK-NEXT:    retq
+; NORECIP-LABEL: reciprocal_square_root:
+; NORECIP:       # BB#0:
+; NORECIP-NEXT:    sqrtss %xmm0, %xmm1
+; NORECIP-NEXT:    movss {{.*#+}} xmm0 = mem[0],zero,zero,zero
+; NORECIP-NEXT:    divss %xmm1, %xmm0
+; NORECIP-NEXT:    retq
 ;
 ; ESTIMATE-LABEL: reciprocal_square_root:
 ; ESTIMATE:       # BB#0:
@@ -89,12 +89,12 @@
 }
 
 define <4 x float> @reciprocal_square_root_v4f32(<4 x float> %x) #0 {
-; CHECK-LABEL: reciprocal_square_root_v4f32:
-; CHECK:       # BB#0:
-; CHECK-NEXT:    sqrtps %xmm0, %xmm1
-; CHECK-NEXT:    movaps {{.*#+}} xmm0 = [1.000000e+00,1.000000e+00,1.000000e+00,1.000000e+00]
-; CHECK-NEXT:    divps %xmm1, %xmm0
-; CHECK-NEXT:    retq
+; NORECIP-LABEL: reciprocal_square_root_v4f32:
+; NORECIP:       # BB#0:
+; NORECIP-NEXT:    sqrtps %xmm0, %xmm1
+; NORECIP-NEXT:    movaps {{.*#+}} xmm0 = [1.000000e+00,1.000000e+00,1.000000e+00,1.000000e+00]
+; NORECIP-NEXT:    divps %xmm1, %xmm0
+; NORECIP-NEXT:    retq
 ;
 ; ESTIMATE-LABEL: reciprocal_square_root_v4f32:
 ; ESTIMATE:       # BB#0:
@@ -111,15 +111,15 @@
 }
 
 define <8 x float> @reciprocal_square_root_v8f32(<8 x float> %x) #0 {
-; CHECK-LABEL: reciprocal_square_root_v8f32:
-; CHECK:       # BB#0:
-; CHECK-NEXT:    sqrtps %xmm1, %xmm2
-; CHECK-NEXT:    sqrtps %xmm0, %xmm3
-; CHECK-NEXT:    movaps {{.*#+}} xmm1 = [1.000000e+00,1.000000e+00,1.000000e+00,1.000000e+00]
-; CHECK-NEXT:    movaps %xmm1, %xmm0
-; CHECK-NEXT:    divps %xmm3, %xmm0
-; CHECK-NEXT:    divps %xmm2, %xmm1
-; CHECK-NEXT:    retq
+; NORECIP-LABEL: reciprocal_square_root_v8f32:
+; NORECIP:       # BB#0:
+; NORECIP-NEXT:    sqrtps %xmm1, %xmm2
+; NORECIP-NEXT:    sqrtps %xmm0, %xmm3
+; NORECIP-NEXT:    movaps {{.*#+}} xmm1 = [1.000000e+00,1.000000e+00,1.000000e+00,1.000000e+00]
+; NORECIP-NEXT:    movaps %xmm1, %xmm0
+; NORECIP-NEXT:    divps %xmm3, %xmm0
+; NORECIP-NEXT:    divps %xmm2, %xmm1
+; NORECIP-NEXT:    retq
 ;
 ; ESTIMATE-LABEL: reciprocal_square_root_v8f32:
 ; ESTIMATE:       # BB#0: