diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index ffb22e1cca4..43c6c9a30e9 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -61,6 +61,26 @@ Non-comprehensive list of changes in this release
 * The optimization flag to merge constants (-fmerge-all-constants) is no longer
   applied by default.
 
+* Optimization of floating-point casts is improved. This may cause surprising
+  results for code that is relying on undefined behavior. Code sanitizers can
+  be used to detect affected patterns such as this:
+
+.. code-block:: c
+
+    int main() {
+      float x = 4294967296.0f;
+      x = (float)((int)x);
+      printf("junk in the ftrunc: %f\n", x);
+      return 0;
+    }
+
+.. code-block:: bash
+
+    clang -O1 ftrunc.c -fsanitize=undefined ; ./a.out 
+    ftrunc.c:5:15: runtime error: 4.29497e+09 is outside the range of representable values of type 'int'
+    junk in the ftrunc: 0.000000
+
+
 * Note..
 
 .. NOTE
diff --git a/include/llvm/CodeGen/ISDOpcodes.h b/include/llvm/CodeGen/ISDOpcodes.h
index ea94871d931..4a516cd6efe 100644
--- a/include/llvm/CodeGen/ISDOpcodes.h
+++ b/include/llvm/CodeGen/ISDOpcodes.h
@@ -495,7 +495,8 @@ namespace ISD {
     ZERO_EXTEND_VECTOR_INREG,
 
     /// FP_TO_[US]INT - Convert a floating point value to a signed or unsigned
-    /// integer.
+    /// integer. These have the same semantics as fptosi and fptoui in IR. If
+    /// the FP value cannot fit in the integer type, the results are undefined.
     FP_TO_SINT,
     FP_TO_UINT,
 
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index abb25fb4f27..879e45df598 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -10890,6 +10890,15 @@ SDValue DAGCombiner::visitSINT_TO_FP(SDNode *N) {
     }
   }
 
+  // fptosi rounds towards zero, so converting from FP to integer and back is
+  // the same as an 'ftrunc': sitofp (fptosi X) --> ftrunc X
+  // We only do this if the target has legal ftrunc, otherwise we'd likely be
+  // replacing casts with a libcall.
+  if (N0.getOpcode() == ISD::FP_TO_SINT &&
+      N0.getOperand(0).getValueType() == VT &&
+      TLI.isOperationLegal(ISD::FTRUNC, VT))
+    return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0.getOperand(0));
+
   return SDValue();
 }
 
@@ -10929,6 +10938,15 @@ SDValue DAGCombiner::visitUINT_TO_FP(SDNode *N) {
     }
   }
 
+  // fptoui rounds towards zero, so converting from FP to integer and back is
+  // the same as an 'ftrunc': uitofp (fptoui X) --> ftrunc X
+  // We only do this if the target has legal ftrunc, otherwise we'd likely be
+  // replacing casts with a libcall.
+  if (N0.getOpcode() == ISD::FP_TO_UINT &&
+      N0.getOperand(0).getValueType() == VT &&
+      TLI.isOperationLegal(ISD::FTRUNC, VT))
+    return DAG.getNode(ISD::FTRUNC, SDLoc(N), VT, N0.getOperand(0));
+
   return SDValue();
 }
 
diff --git a/test/CodeGen/AArch64/ftrunc.ll b/test/CodeGen/AArch64/ftrunc.ll
index 03284e9cc0c..788b06d8233 100644
--- a/test/CodeGen/AArch64/ftrunc.ll
+++ b/test/CodeGen/AArch64/ftrunc.ll
@@ -4,8 +4,7 @@
 define float @trunc_unsigned_f32(float %x) {
 ; CHECK-LABEL: trunc_unsigned_f32:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    fcvtzu w8, s0
-; CHECK-NEXT:    ucvtf s0, w8
+; CHECK-NEXT:    frintz s0, s0
 ; CHECK-NEXT:    ret
   %i = fptoui float %x to i32
   %r = uitofp i32 %i to float
@@ -15,8 +14,7 @@ define float @trunc_unsigned_f32(float %x) {
 define double @trunc_unsigned_f64(double %x) {
 ; CHECK-LABEL: trunc_unsigned_f64:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    fcvtzu x8, d0
-; CHECK-NEXT:    ucvtf d0, x8
+; CHECK-NEXT:    frintz d0, d0
 ; CHECK-NEXT:    ret
   %i = fptoui double %x to i64
   %r = uitofp i64 %i to double
@@ -26,8 +24,7 @@ define double @trunc_unsigned_f64(double %x) {
 define float @trunc_signed_f32(float %x) {
 ; CHECK-LABEL: trunc_signed_f32:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    fcvtzs w8, s0
-; CHECK-NEXT:    scvtf s0, w8
+; CHECK-NEXT:    frintz s0, s0
 ; CHECK-NEXT:    ret
   %i = fptosi float %x to i32
   %r = sitofp i32 %i to float
@@ -37,8 +34,7 @@ define float @trunc_signed_f32(float %x) {
 define double @trunc_signed_f64(double %x) {
 ; CHECK-LABEL: trunc_signed_f64:
 ; CHECK:       // %bb.0:
-; CHECK-NEXT:    fcvtzs x8, d0
-; CHECK-NEXT:    scvtf d0, x8
+; CHECK-NEXT:    frintz d0, d0
 ; CHECK-NEXT:    ret
   %i = fptosi double %x to i64
   %r = sitofp i64 %i to double
diff --git a/test/CodeGen/ARM/ftrunc.ll b/test/CodeGen/ARM/ftrunc.ll
new file mode 100644
index 00000000000..26cf93fc835
--- /dev/null
+++ b/test/CodeGen/ARM/ftrunc.ll
@@ -0,0 +1,42 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=armv7-eabi < %s | FileCheck %s
+
+define float @trunc_unsigned_f32(float %x) nounwind {
+; CHECK-LABEL: trunc_unsigned_f32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    vmov s0, r0
+; CHECK-NEXT:    vcvt.u32.f32 s0, s0
+; CHECK-NEXT:    vcvt.f32.u32 s0, s0
+; CHECK-NEXT:    vmov r0, s0
+; CHECK-NEXT:    bx lr
+  %i = fptoui float %x to i32
+  %r = uitofp i32 %i to float
+  ret float %r
+}
+
+define double @trunc_unsigned_f64_i64(double %x) nounwind {
+; CHECK-LABEL: trunc_unsigned_f64_i64:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    .save {r11, lr}
+; CHECK-NEXT:    push {r11, lr}
+; CHECK-NEXT:    bl __aeabi_d2ulz
+; CHECK-NEXT:    bl __aeabi_ul2d
+; CHECK-NEXT:    pop {r11, pc}
+  %i = fptoui double %x to i64
+  %r = uitofp i64 %i to double
+  ret double %r
+}
+
+define double @trunc_unsigned_f64_i32(double %x) nounwind {
+; CHECK-LABEL: trunc_unsigned_f64_i32:
+; CHECK:       @ %bb.0:
+; CHECK-NEXT:    vmov d16, r0, r1
+; CHECK-NEXT:    vcvt.u32.f64 s0, d16
+; CHECK-NEXT:    vcvt.f64.u32 d16, s0
+; CHECK-NEXT:    vmov r0, r1, d16
+; CHECK-NEXT:    bx lr
+  %i = fptoui double %x to i32
+  %r = uitofp i32 %i to double
+  ret double %r
+}
+
diff --git a/test/CodeGen/PowerPC/fp-int128-fp-combine.ll b/test/CodeGen/PowerPC/fp-int128-fp-combine.ll
index eff0c28e0f5..4a36f2404b6 100644
--- a/test/CodeGen/PowerPC/fp-int128-fp-combine.ll
+++ b/test/CodeGen/PowerPC/fp-int128-fp-combine.ll
@@ -5,18 +5,7 @@
 define float @f_i128_f(float %v) {
 ; CHECK-LABEL: f_i128_f:
 ; CHECK:       # %bb.0: # %entry
-; CHECK-NEXT:    mflr 0
-; CHECK-NEXT:    std 0, 16(1)
-; CHECK-NEXT:    stdu 1, -32(1)
-; CHECK-NEXT:    .cfi_def_cfa_offset 32
-; CHECK-NEXT:    .cfi_offset lr, 16
-; CHECK-NEXT:    bl __fixsfti
-; CHECK-NEXT:    nop
-; CHECK-NEXT:    bl __floattisf
-; CHECK-NEXT:    nop
-; CHECK-NEXT:    addi 1, 1, 32
-; CHECK-NEXT:    ld 0, 16(1)
-; CHECK-NEXT:    mtlr 0
+; CHECK-NEXT:    friz 1, 1
 ; CHECK-NEXT:    blr
 entry:
   %a = fptosi float %v to i128
diff --git a/test/CodeGen/PowerPC/fp-to-int-to-fp.ll b/test/CodeGen/PowerPC/fp-to-int-to-fp.ll
index be55d4ab853..942bdf5e028 100644
--- a/test/CodeGen/PowerPC/fp-to-int-to-fp.ll
+++ b/test/CodeGen/PowerPC/fp-to-int-to-fp.ll
@@ -11,8 +11,7 @@ entry:
   ret float %conv1
 
 ; FPCVT-LABEL: @fool
-; FPCVT: fctidz [[REG1:[0-9]+]], 1
-; FPCVT: fcfids 1, [[REG1]]
+; FPCVT: friz 1, 1
 ; FPCVT: blr
 
 ; PPC64-LABEL: @fool
@@ -30,8 +29,7 @@ entry:
   ret double %conv1
 
 ; FPCVT-LABEL: @foodl
-; FPCVT: fctidz [[REG1:[0-9]+]], 1
-; FPCVT: fcfid 1, [[REG1]]
+; FPCVT: friz 1, 1
 ; FPCVT: blr
 
 ; PPC64-LABEL: @foodl
@@ -48,8 +46,7 @@ entry:
   ret float %conv1
 
 ; FPCVT-LABEL: @fooul
-; FPCVT: fctiduz [[REG1:[0-9]+]], 1
-; FPCVT: fcfidus 1, [[REG1]]
+; FPCVT: friz 1, 1
 ; FPCVT: blr
 }
 
@@ -61,8 +58,7 @@ entry:
   ret double %conv1
 
 ; FPCVT-LABEL: @fooudl
-; FPCVT: fctiduz [[REG1:[0-9]+]], 1
-; FPCVT: fcfidu 1, [[REG1]]
+; FPCVT: friz 1, 1
 ; FPCVT: blr
 }
 
diff --git a/test/CodeGen/PowerPC/ftrunc-vec.ll b/test/CodeGen/PowerPC/ftrunc-vec.ll
index 99f21a117d5..ef529ed254e 100644
--- a/test/CodeGen/PowerPC/ftrunc-vec.ll
+++ b/test/CodeGen/PowerPC/ftrunc-vec.ll
@@ -4,8 +4,7 @@
 define <4 x float> @truncf32(<4 x float> %a) {
 ; CHECK-LABEL: truncf32:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    xvcvspsxws 0, 34
-; CHECK-NEXT:    xvcvsxwsp 34, 0
+; CHECK-NEXT:    xvrspiz 34, 34
 ; CHECK-NEXT:    blr
   %t0 = fptosi <4 x float> %a to <4 x i32>
   %t1 = sitofp <4 x i32> %t0 to <4 x float>
@@ -15,8 +14,7 @@ define <4 x float> @truncf32(<4 x float> %a) {
 define <2 x double> @truncf64(<2 x double> %a) {
 ; CHECK-LABEL: truncf64:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    xvcvdpsxds 34, 34
-; CHECK-NEXT:    xvcvsxddp 34, 34
+; CHECK-NEXT:    xvrdpiz 34, 34
 ; CHECK-NEXT:    blr
   %t0 = fptosi <2 x double> %a to <2 x i64>
   %t1 = sitofp <2 x i64> %t0 to <2 x double>
@@ -26,8 +24,7 @@ define <2 x double> @truncf64(<2 x double> %a) {
 define <4 x float> @truncf32u(<4 x float> %a) {
 ; CHECK-LABEL: truncf32u:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    xvcvspuxws 0, 34
-; CHECK-NEXT:    xvcvuxwsp 34, 0
+; CHECK-NEXT:    xvrspiz 34, 34
 ; CHECK-NEXT:    blr
   %t0 = fptoui <4 x float> %a to <4 x i32>
   %t1 = uitofp <4 x i32> %t0 to <4 x float>
@@ -37,8 +34,7 @@ define <4 x float> @truncf32u(<4 x float> %a) {
 define <2 x double> @truncf64u(<2 x double> %a) {
 ; CHECK-LABEL: truncf64u:
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    xvcvdpuxds 34, 34
-; CHECK-NEXT:    xvcvuxddp 34, 34
+; CHECK-NEXT:    xvrdpiz 34, 34
 ; CHECK-NEXT:    blr
   %t0 = fptoui <2 x double> %a to <2 x i64>
   %t1 = uitofp <2 x i64> %t0 to <2 x double>
diff --git a/test/CodeGen/PowerPC/no-extra-fp-conv-ldst.ll b/test/CodeGen/PowerPC/no-extra-fp-conv-ldst.ll
index 713adb4dfd0..0bbaf3493fd 100644
--- a/test/CodeGen/PowerPC/no-extra-fp-conv-ldst.ll
+++ b/test/CodeGen/PowerPC/no-extra-fp-conv-ldst.ll
@@ -36,11 +36,7 @@ entry:
   ret float %conv1
 
 ; CHECK-LABEL: @foo
-; CHECK-DAG: fctiwz [[REG2:[0-9]+]], 1
-; CHECK-DAG: addi [[REG1:[0-9]+]], 1,
-; CHECK: stfiwx [[REG2]], 0, [[REG1]]
-; CHECK: lfiwax [[REG3:[0-9]+]], 0, [[REG1]]
-; CHECK: fcfids 1, [[REG3]]
+; CHECK: friz 1, 1
 ; CHECK: blr
 }
 
@@ -52,11 +48,7 @@ entry:
   ret double %conv1
 
 ; CHECK-LABEL: @food
-; CHECK-DAG: fctiwz [[REG2:[0-9]+]], 1
-; CHECK-DAG: addi [[REG1:[0-9]+]], 1,
-; CHECK: stfiwx [[REG2]], 0, [[REG1]]
-; CHECK: lfiwax [[REG3:[0-9]+]], 0, [[REG1]]
-; CHECK: fcfid 1, [[REG3]]
+; CHECK: friz 1, 1
 ; CHECK: blr
 }
 
@@ -68,11 +60,7 @@ entry:
   ret float %conv1
 
 ; CHECK-LABEL: @foou
-; CHECK-DAG: fctiwuz [[REG2:[0-9]+]], 1
-; CHECK-DAG: addi [[REG1:[0-9]+]], 1,
-; CHECK: stfiwx [[REG2]], 0, [[REG1]]
-; CHECK: lfiwzx [[REG3:[0-9]+]], 0, [[REG1]]
-; CHECK: fcfidus 1, [[REG3]]
+; CHECK: friz 1, 1
 ; CHECK: blr
 }
 
@@ -84,11 +72,7 @@ entry:
   ret double %conv1
 
 ; CHECK-LABEL: @fooud
-; CHECK-DAG: fctiwuz [[REG2:[0-9]+]], 1
-; CHECK-DAG: addi [[REG1:[0-9]+]], 1,
-; CHECK: stfiwx [[REG2]], 0, [[REG1]]
-; CHECK: lfiwzx [[REG3:[0-9]+]], 0, [[REG1]]
-; CHECK: fcfidu 1, [[REG3]]
+; CHECK: friz 1, 1
 ; CHECK: blr
 }
 
diff --git a/test/CodeGen/X86/2011-10-19-widen_vselect.ll b/test/CodeGen/X86/2011-10-19-widen_vselect.ll
index c98bafcd565..d11f4efdafc 100644
--- a/test/CodeGen/X86/2011-10-19-widen_vselect.ll
+++ b/test/CodeGen/X86/2011-10-19-widen_vselect.ll
@@ -71,8 +71,7 @@ define void @full_test() {
 ; X32-NEXT:    subl $60, %esp
 ; X32-NEXT:    .cfi_def_cfa_offset 64
 ; X32-NEXT:    movsd {{.*#+}} xmm2 = mem[0],zero
-; X32-NEXT:    cvttps2dq %xmm2, %xmm0
-; X32-NEXT:    cvtdq2ps %xmm0, %xmm1
+; X32-NEXT:    roundps $11, %xmm2, %xmm1
 ; X32-NEXT:    xorps %xmm0, %xmm0
 ; X32-NEXT:    cmpltps %xmm2, %xmm0
 ; X32-NEXT:    movaps {{.*#+}} xmm3 = <1,1,u,u>
@@ -93,8 +92,7 @@ define void @full_test() {
 ; X64-LABEL: full_test:
 ; X64:       # %bb.0: # %entry
 ; X64-NEXT:    movsd {{.*#+}} xmm2 = mem[0],zero
-; X64-NEXT:    cvttps2dq %xmm2, %xmm0
-; X64-NEXT:    cvtdq2ps %xmm0, %xmm1
+; X64-NEXT:    roundps $11, %xmm2, %xmm1
 ; X64-NEXT:    xorps %xmm0, %xmm0
 ; X64-NEXT:    cmpltps %xmm2, %xmm0
 ; X64-NEXT:    movaps {{.*#+}} xmm3 = <1,1,u,u>
diff --git a/test/CodeGen/X86/ftrunc.ll b/test/CodeGen/X86/ftrunc.ll
index 1cdc34a372b..5f95119195e 100644
--- a/test/CodeGen/X86/ftrunc.ll
+++ b/test/CodeGen/X86/ftrunc.ll
@@ -14,17 +14,12 @@ define float @trunc_unsigned_f32(float %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_unsigned_f32:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    cvttss2si %xmm0, %rax
-; SSE41-NEXT:    movl %eax, %eax
-; SSE41-NEXT:    xorps %xmm0, %xmm0
-; SSE41-NEXT:    cvtsi2ssq %rax, %xmm0
+; SSE41-NEXT:    roundss $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_unsigned_f32:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vcvttss2si %xmm0, %rax
-; AVX1-NEXT:    movl %eax, %eax
-; AVX1-NEXT:    vcvtsi2ssq %rax, %xmm1, %xmm0
+; AVX1-NEXT:    vroundss $11, %xmm0, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptoui float %x to i32
   %r = uitofp i32 %i to float
@@ -52,35 +47,12 @@ define double @trunc_unsigned_f64(double %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_unsigned_f64:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    movsd {{.*#+}} xmm1 = mem[0],zero
-; SSE41-NEXT:    movapd %xmm0, %xmm2
-; SSE41-NEXT:    subsd %xmm1, %xmm2
-; SSE41-NEXT:    cvttsd2si %xmm2, %rax
-; SSE41-NEXT:    movabsq $-9223372036854775808, %rcx # imm = 0x8000000000000000
-; SSE41-NEXT:    xorq %rax, %rcx
-; SSE41-NEXT:    cvttsd2si %xmm0, %rax
-; SSE41-NEXT:    ucomisd %xmm1, %xmm0
-; SSE41-NEXT:    cmovaeq %rcx, %rax
-; SSE41-NEXT:    movq %rax, %xmm0
-; SSE41-NEXT:    punpckldq {{.*#+}} xmm0 = xmm0[0],mem[0],xmm0[1],mem[1]
-; SSE41-NEXT:    subpd {{.*}}(%rip), %xmm0
-; SSE41-NEXT:    haddpd %xmm0, %xmm0
+; SSE41-NEXT:    roundsd $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_unsigned_f64:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vmovsd {{.*#+}} xmm1 = mem[0],zero
-; AVX1-NEXT:    vsubsd %xmm1, %xmm0, %xmm2
-; AVX1-NEXT:    vcvttsd2si %xmm2, %rax
-; AVX1-NEXT:    movabsq $-9223372036854775808, %rcx # imm = 0x8000000000000000
-; AVX1-NEXT:    xorq %rax, %rcx
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rax
-; AVX1-NEXT:    vucomisd %xmm1, %xmm0
-; AVX1-NEXT:    cmovaeq %rcx, %rax
-; AVX1-NEXT:    vmovq %rax, %xmm0
-; AVX1-NEXT:    vpunpckldq {{.*#+}} xmm0 = xmm0[0],mem[0],xmm0[1],mem[1]
-; AVX1-NEXT:    vsubpd {{.*}}(%rip), %xmm0, %xmm0
-; AVX1-NEXT:    vhaddpd %xmm0, %xmm0, %xmm0
+; AVX1-NEXT:    vroundsd $11, %xmm0, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptoui double %x to i64
   %r = uitofp i64 %i to double
@@ -118,45 +90,12 @@ define <4 x float> @trunc_unsigned_v4f32(<4 x float> %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_unsigned_v4f32:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    movshdup {{.*#+}} xmm1 = xmm0[1,1,3,3]
-; SSE41-NEXT:    cvttss2si %xmm1, %rax
-; SSE41-NEXT:    cvttss2si %xmm0, %rcx
-; SSE41-NEXT:    movd %ecx, %xmm1
-; SSE41-NEXT:    pinsrd $1, %eax, %xmm1
-; SSE41-NEXT:    movaps %xmm0, %xmm2
-; SSE41-NEXT:    movhlps {{.*#+}} xmm2 = xmm0[1],xmm2[1]
-; SSE41-NEXT:    cvttss2si %xmm2, %rax
-; SSE41-NEXT:    pinsrd $2, %eax, %xmm1
-; SSE41-NEXT:    shufps {{.*#+}} xmm0 = xmm0[3,1,2,3]
-; SSE41-NEXT:    cvttss2si %xmm0, %rax
-; SSE41-NEXT:    pinsrd $3, %eax, %xmm1
-; SSE41-NEXT:    movdqa {{.*#+}} xmm0 = [1258291200,1258291200,1258291200,1258291200]
-; SSE41-NEXT:    pblendw {{.*#+}} xmm0 = xmm1[0],xmm0[1],xmm1[2],xmm0[3],xmm1[4],xmm0[5],xmm1[6],xmm0[7]
-; SSE41-NEXT:    psrld $16, %xmm1
-; SSE41-NEXT:    pblendw {{.*#+}} xmm1 = xmm1[0],mem[1],xmm1[2],mem[3],xmm1[4],mem[5],xmm1[6],mem[7]
-; SSE41-NEXT:    addps {{.*}}(%rip), %xmm1
-; SSE41-NEXT:    addps %xmm0, %xmm1
-; SSE41-NEXT:    movaps %xmm1, %xmm0
+; SSE41-NEXT:    roundps $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_unsigned_v4f32:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vmovshdup {{.*#+}} xmm1 = xmm0[1,1,3,3]
-; AVX1-NEXT:    vcvttss2si %xmm1, %rax
-; AVX1-NEXT:    vcvttss2si %xmm0, %rcx
-; AVX1-NEXT:    vmovd %ecx, %xmm1
-; AVX1-NEXT:    vpinsrd $1, %eax, %xmm1, %xmm1
-; AVX1-NEXT:    vpermilpd {{.*#+}} xmm2 = xmm0[1,0]
-; AVX1-NEXT:    vcvttss2si %xmm2, %rax
-; AVX1-NEXT:    vpinsrd $2, %eax, %xmm1, %xmm1
-; AVX1-NEXT:    vpermilps {{.*#+}} xmm0 = xmm0[3,1,2,3]
-; AVX1-NEXT:    vcvttss2si %xmm0, %rax
-; AVX1-NEXT:    vpinsrd $3, %eax, %xmm1, %xmm0
-; AVX1-NEXT:    vpblendw {{.*#+}} xmm1 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; AVX1-NEXT:    vpsrld $16, %xmm0, %xmm0
-; AVX1-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; AVX1-NEXT:    vaddps {{.*}}(%rip), %xmm0, %xmm0
-; AVX1-NEXT:    vaddps %xmm0, %xmm1, %xmm0
+; AVX1-NEXT:    vroundps $11, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptoui <4 x float> %x to <4 x i32>
   %r = uitofp <4 x i32> %i to <4 x float>
@@ -201,61 +140,12 @@ define <2 x double> @trunc_unsigned_v2f64(<2 x double> %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_unsigned_v2f64:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    movaps %xmm0, %xmm1
-; SSE41-NEXT:    movhlps {{.*#+}} xmm1 = xmm0[1],xmm1[1]
-; SSE41-NEXT:    movsd {{.*#+}} xmm2 = mem[0],zero
-; SSE41-NEXT:    movaps %xmm1, %xmm3
-; SSE41-NEXT:    subsd %xmm2, %xmm3
-; SSE41-NEXT:    cvttsd2si %xmm3, %rax
-; SSE41-NEXT:    movabsq $-9223372036854775808, %rcx # imm = 0x8000000000000000
-; SSE41-NEXT:    xorq %rcx, %rax
-; SSE41-NEXT:    cvttsd2si %xmm1, %rdx
-; SSE41-NEXT:    ucomisd %xmm2, %xmm1
-; SSE41-NEXT:    cmovaeq %rax, %rdx
-; SSE41-NEXT:    movaps %xmm0, %xmm1
-; SSE41-NEXT:    subsd %xmm2, %xmm1
-; SSE41-NEXT:    cvttsd2si %xmm1, %rax
-; SSE41-NEXT:    xorq %rcx, %rax
-; SSE41-NEXT:    cvttsd2si %xmm0, %rcx
-; SSE41-NEXT:    ucomisd %xmm2, %xmm0
-; SSE41-NEXT:    cmovaeq %rax, %rcx
-; SSE41-NEXT:    movq %rcx, %xmm0
-; SSE41-NEXT:    movdqa {{.*#+}} xmm1 = [1127219200,1160773632,0,0]
-; SSE41-NEXT:    punpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
-; SSE41-NEXT:    movapd {{.*#+}} xmm2 = [4.503600e+15,1.934281e+25]
-; SSE41-NEXT:    subpd %xmm2, %xmm0
-; SSE41-NEXT:    movq %rdx, %xmm3
-; SSE41-NEXT:    punpckldq {{.*#+}} xmm3 = xmm3[0],xmm1[0],xmm3[1],xmm1[1]
-; SSE41-NEXT:    subpd %xmm2, %xmm3
-; SSE41-NEXT:    haddpd %xmm3, %xmm0
+; SSE41-NEXT:    roundpd $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_unsigned_v2f64:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm0[1,0]
-; AVX1-NEXT:    vmovsd {{.*#+}} xmm2 = mem[0],zero
-; AVX1-NEXT:    vsubsd %xmm2, %xmm1, %xmm3
-; AVX1-NEXT:    vcvttsd2si %xmm3, %rax
-; AVX1-NEXT:    movabsq $-9223372036854775808, %rcx # imm = 0x8000000000000000
-; AVX1-NEXT:    xorq %rcx, %rax
-; AVX1-NEXT:    vcvttsd2si %xmm1, %rdx
-; AVX1-NEXT:    vucomisd %xmm2, %xmm1
-; AVX1-NEXT:    cmovaeq %rax, %rdx
-; AVX1-NEXT:    vsubsd %xmm2, %xmm0, %xmm1
-; AVX1-NEXT:    vcvttsd2si %xmm1, %rax
-; AVX1-NEXT:    xorq %rcx, %rax
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rcx
-; AVX1-NEXT:    vucomisd %xmm2, %xmm0
-; AVX1-NEXT:    cmovaeq %rax, %rcx
-; AVX1-NEXT:    vmovq %rcx, %xmm0
-; AVX1-NEXT:    vmovdqa {{.*#+}} xmm1 = [1127219200,1160773632,0,0]
-; AVX1-NEXT:    vpunpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
-; AVX1-NEXT:    vmovapd {{.*#+}} xmm2 = [4.503600e+15,1.934281e+25]
-; AVX1-NEXT:    vsubpd %xmm2, %xmm0, %xmm0
-; AVX1-NEXT:    vmovq %rdx, %xmm3
-; AVX1-NEXT:    vpunpckldq {{.*#+}} xmm1 = xmm3[0],xmm1[0],xmm3[1],xmm1[1]
-; AVX1-NEXT:    vsubpd %xmm2, %xmm1, %xmm1
-; AVX1-NEXT:    vhaddpd %xmm1, %xmm0, %xmm0
+; AVX1-NEXT:    vroundpd $11, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptoui <2 x double> %x to <2 x i64>
   %r = uitofp <2 x i64> %i to <2 x double>
@@ -327,106 +217,13 @@ define <4 x double> @trunc_unsigned_v4f64(<4 x double> %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_unsigned_v4f64:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    movaps %xmm1, %xmm3
-; SSE41-NEXT:    movhlps {{.*#+}} xmm3 = xmm1[1],xmm3[1]
-; SSE41-NEXT:    movsd {{.*#+}} xmm2 = mem[0],zero
-; SSE41-NEXT:    movaps %xmm3, %xmm4
-; SSE41-NEXT:    subsd %xmm2, %xmm4
-; SSE41-NEXT:    cvttsd2si %xmm4, %rcx
-; SSE41-NEXT:    movabsq $-9223372036854775808, %rdx # imm = 0x8000000000000000
-; SSE41-NEXT:    xorq %rdx, %rcx
-; SSE41-NEXT:    cvttsd2si %xmm3, %rax
-; SSE41-NEXT:    ucomisd %xmm2, %xmm3
-; SSE41-NEXT:    cmovaeq %rcx, %rax
-; SSE41-NEXT:    movaps %xmm1, %xmm3
-; SSE41-NEXT:    subsd %xmm2, %xmm3
-; SSE41-NEXT:    cvttsd2si %xmm3, %rsi
-; SSE41-NEXT:    xorq %rdx, %rsi
-; SSE41-NEXT:    cvttsd2si %xmm1, %rcx
-; SSE41-NEXT:    ucomisd %xmm2, %xmm1
-; SSE41-NEXT:    cmovaeq %rsi, %rcx
-; SSE41-NEXT:    movaps %xmm0, %xmm1
-; SSE41-NEXT:    movhlps {{.*#+}} xmm1 = xmm0[1],xmm1[1]
-; SSE41-NEXT:    movaps %xmm1, %xmm3
-; SSE41-NEXT:    subsd %xmm2, %xmm3
-; SSE41-NEXT:    cvttsd2si %xmm3, %rsi
-; SSE41-NEXT:    xorq %rdx, %rsi
-; SSE41-NEXT:    cvttsd2si %xmm1, %rdi
-; SSE41-NEXT:    ucomisd %xmm2, %xmm1
-; SSE41-NEXT:    cmovaeq %rsi, %rdi
-; SSE41-NEXT:    movaps %xmm0, %xmm1
-; SSE41-NEXT:    subsd %xmm2, %xmm1
-; SSE41-NEXT:    cvttsd2si %xmm1, %rsi
-; SSE41-NEXT:    xorq %rdx, %rsi
-; SSE41-NEXT:    cvttsd2si %xmm0, %rdx
-; SSE41-NEXT:    ucomisd %xmm2, %xmm0
-; SSE41-NEXT:    cmovaeq %rsi, %rdx
-; SSE41-NEXT:    movq %rdx, %xmm0
-; SSE41-NEXT:    movdqa {{.*#+}} xmm2 = [1127219200,1160773632,0,0]
-; SSE41-NEXT:    punpckldq {{.*#+}} xmm0 = xmm0[0],xmm2[0],xmm0[1],xmm2[1]
-; SSE41-NEXT:    movapd {{.*#+}} xmm3 = [4.503600e+15,1.934281e+25]
-; SSE41-NEXT:    subpd %xmm3, %xmm0
-; SSE41-NEXT:    movq %rdi, %xmm1
-; SSE41-NEXT:    punpckldq {{.*#+}} xmm1 = xmm1[0],xmm2[0],xmm1[1],xmm2[1]
-; SSE41-NEXT:    subpd %xmm3, %xmm1
-; SSE41-NEXT:    haddpd %xmm1, %xmm0
-; SSE41-NEXT:    movq %rcx, %xmm1
-; SSE41-NEXT:    punpckldq {{.*#+}} xmm1 = xmm1[0],xmm2[0],xmm1[1],xmm2[1]
-; SSE41-NEXT:    subpd %xmm3, %xmm1
-; SSE41-NEXT:    movq %rax, %xmm4
-; SSE41-NEXT:    punpckldq {{.*#+}} xmm4 = xmm4[0],xmm2[0],xmm4[1],xmm2[1]
-; SSE41-NEXT:    subpd %xmm3, %xmm4
-; SSE41-NEXT:    haddpd %xmm4, %xmm1
+; SSE41-NEXT:    roundpd $11, %xmm0, %xmm0
+; SSE41-NEXT:    roundpd $11, %xmm1, %xmm1
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_unsigned_v4f64:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vpermilpd {{.*#+}} xmm2 = xmm0[1,0]
-; AVX1-NEXT:    vmovsd {{.*#+}} xmm1 = mem[0],zero
-; AVX1-NEXT:    vsubsd %xmm1, %xmm2, %xmm3
-; AVX1-NEXT:    vcvttsd2si %xmm3, %rcx
-; AVX1-NEXT:    movabsq $-9223372036854775808, %rdx # imm = 0x8000000000000000
-; AVX1-NEXT:    xorq %rdx, %rcx
-; AVX1-NEXT:    vcvttsd2si %xmm2, %rax
-; AVX1-NEXT:    vucomisd %xmm1, %xmm2
-; AVX1-NEXT:    cmovaeq %rcx, %rax
-; AVX1-NEXT:    vsubsd %xmm1, %xmm0, %xmm2
-; AVX1-NEXT:    vcvttsd2si %xmm2, %rcx
-; AVX1-NEXT:    xorq %rdx, %rcx
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rsi
-; AVX1-NEXT:    vucomisd %xmm1, %xmm0
-; AVX1-NEXT:    cmovaeq %rcx, %rsi
-; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm0
-; AVX1-NEXT:    vpermilpd {{.*#+}} xmm2 = xmm0[1,0]
-; AVX1-NEXT:    vsubsd %xmm1, %xmm2, %xmm3
-; AVX1-NEXT:    vcvttsd2si %xmm3, %rcx
-; AVX1-NEXT:    xorq %rdx, %rcx
-; AVX1-NEXT:    vcvttsd2si %xmm2, %rdi
-; AVX1-NEXT:    vucomisd %xmm1, %xmm2
-; AVX1-NEXT:    cmovaeq %rcx, %rdi
-; AVX1-NEXT:    vsubsd %xmm1, %xmm0, %xmm2
-; AVX1-NEXT:    vcvttsd2si %xmm2, %rcx
-; AVX1-NEXT:    xorq %rdx, %rcx
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rdx
-; AVX1-NEXT:    vucomisd %xmm1, %xmm0
-; AVX1-NEXT:    cmovaeq %rcx, %rdx
-; AVX1-NEXT:    vmovq %rdx, %xmm0
-; AVX1-NEXT:    vmovdqa {{.*#+}} xmm1 = [1127219200,1160773632,0,0]
-; AVX1-NEXT:    vpunpckldq {{.*#+}} xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
-; AVX1-NEXT:    vmovapd {{.*#+}} xmm2 = [4.503600e+15,1.934281e+25]
-; AVX1-NEXT:    vsubpd %xmm2, %xmm0, %xmm0
-; AVX1-NEXT:    vmovq %rdi, %xmm3
-; AVX1-NEXT:    vpunpckldq {{.*#+}} xmm3 = xmm3[0],xmm1[0],xmm3[1],xmm1[1]
-; AVX1-NEXT:    vsubpd %xmm2, %xmm3, %xmm3
-; AVX1-NEXT:    vhaddpd %xmm3, %xmm0, %xmm0
-; AVX1-NEXT:    vmovq %rsi, %xmm3
-; AVX1-NEXT:    vpunpckldq {{.*#+}} xmm3 = xmm3[0],xmm1[0],xmm3[1],xmm1[1]
-; AVX1-NEXT:    vsubpd %xmm2, %xmm3, %xmm3
-; AVX1-NEXT:    vmovq %rax, %xmm4
-; AVX1-NEXT:    vpunpckldq {{.*#+}} xmm1 = xmm4[0],xmm1[0],xmm4[1],xmm1[1]
-; AVX1-NEXT:    vsubpd %xmm2, %xmm1, %xmm1
-; AVX1-NEXT:    vhaddpd %xmm1, %xmm3, %xmm1
-; AVX1-NEXT:    vinsertf128 $1, %xmm0, %ymm1, %ymm0
+; AVX1-NEXT:    vroundpd $11, %ymm0, %ymm0
 ; AVX1-NEXT:    retq
   %i = fptoui <4 x double> %x to <4 x i64>
   %r = uitofp <4 x i64> %i to <4 x double>
@@ -443,15 +240,12 @@ define float @trunc_signed_f32(float %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_signed_f32:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    cvttss2si %xmm0, %eax
-; SSE41-NEXT:    xorps %xmm0, %xmm0
-; SSE41-NEXT:    cvtsi2ssl %eax, %xmm0
+; SSE41-NEXT:    roundss $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_signed_f32:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vcvttss2si %xmm0, %eax
-; AVX1-NEXT:    vcvtsi2ssl %eax, %xmm1, %xmm0
+; AVX1-NEXT:    vroundss $11, %xmm0, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptosi float %x to i32
   %r = sitofp i32 %i to float
@@ -468,15 +262,12 @@ define double @trunc_signed_f64(double %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_signed_f64:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    cvttsd2si %xmm0, %rax
-; SSE41-NEXT:    xorps %xmm0, %xmm0
-; SSE41-NEXT:    cvtsi2sdq %rax, %xmm0
+; SSE41-NEXT:    roundsd $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_signed_f64:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rax
-; AVX1-NEXT:    vcvtsi2sdq %rax, %xmm1, %xmm0
+; AVX1-NEXT:    vroundsd $11, %xmm0, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptosi double %x to i64
   %r = sitofp i64 %i to double
@@ -492,14 +283,12 @@ define <4 x float> @trunc_signed_v4f32(<4 x float> %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_signed_v4f32:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    cvttps2dq %xmm0, %xmm0
-; SSE41-NEXT:    cvtdq2ps %xmm0, %xmm0
+; SSE41-NEXT:    roundps $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_signed_v4f32:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vcvttps2dq %xmm0, %xmm0
-; AVX1-NEXT:    vcvtdq2ps %xmm0, %xmm0
+; AVX1-NEXT:    vroundps $11, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptosi <4 x float> %x to <4 x i32>
   %r = sitofp <4 x i32> %i to <4 x float>
@@ -520,23 +309,12 @@ define <2 x double> @trunc_signed_v2f64(<2 x double> %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_signed_v2f64:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    cvttsd2si %xmm0, %rax
-; SSE41-NEXT:    movhlps {{.*#+}} xmm0 = xmm0[1,1]
-; SSE41-NEXT:    cvttsd2si %xmm0, %rcx
-; SSE41-NEXT:    xorps %xmm0, %xmm0
-; SSE41-NEXT:    cvtsi2sdq %rax, %xmm0
-; SSE41-NEXT:    cvtsi2sdq %rcx, %xmm1
-; SSE41-NEXT:    movlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; SSE41-NEXT:    roundpd $11, %xmm0, %xmm0
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_signed_v2f64:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm0[1,0]
-; AVX1-NEXT:    vcvttsd2si %xmm1, %rax
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rcx
-; AVX1-NEXT:    vcvtsi2sdq %rcx, %xmm2, %xmm0
-; AVX1-NEXT:    vcvtsi2sdq %rax, %xmm2, %xmm1
-; AVX1-NEXT:    vmovlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
+; AVX1-NEXT:    vroundpd $11, %xmm0, %xmm0
 ; AVX1-NEXT:    retq
   %i = fptosi <2 x double> %x to <2 x i64>
   %r = sitofp <2 x i64> %i to <2 x double>
@@ -565,39 +343,13 @@ define <4 x double> @trunc_signed_v4f64(<4 x double> %x) nounwind {
 ;
 ; SSE41-LABEL: trunc_signed_v4f64:
 ; SSE41:       # %bb.0:
-; SSE41-NEXT:    cvttsd2si %xmm1, %rax
-; SSE41-NEXT:    movhlps {{.*#+}} xmm1 = xmm1[1,1]
-; SSE41-NEXT:    cvttsd2si %xmm1, %rcx
-; SSE41-NEXT:    cvttsd2si %xmm0, %rdx
-; SSE41-NEXT:    movhlps {{.*#+}} xmm0 = xmm0[1,1]
-; SSE41-NEXT:    cvttsd2si %xmm0, %rsi
-; SSE41-NEXT:    xorps %xmm0, %xmm0
-; SSE41-NEXT:    cvtsi2sdq %rdx, %xmm0
-; SSE41-NEXT:    xorps %xmm1, %xmm1
-; SSE41-NEXT:    cvtsi2sdq %rsi, %xmm1
-; SSE41-NEXT:    movlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
-; SSE41-NEXT:    xorps %xmm1, %xmm1
-; SSE41-NEXT:    cvtsi2sdq %rax, %xmm1
-; SSE41-NEXT:    cvtsi2sdq %rcx, %xmm2
-; SSE41-NEXT:    movlhps {{.*#+}} xmm1 = xmm1[0],xmm2[0]
+; SSE41-NEXT:    roundpd $11, %xmm0, %xmm0
+; SSE41-NEXT:    roundpd $11, %xmm1, %xmm1
 ; SSE41-NEXT:    retq
 ;
 ; AVX1-LABEL: trunc_signed_v4f64:
 ; AVX1:       # %bb.0:
-; AVX1-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm0[1,0]
-; AVX1-NEXT:    vcvttsd2si %xmm1, %rax
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rcx
-; AVX1-NEXT:    vextractf128 $1, %ymm0, %xmm0
-; AVX1-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm0[1,0]
-; AVX1-NEXT:    vcvttsd2si %xmm1, %rdx
-; AVX1-NEXT:    vcvttsd2si %xmm0, %rsi
-; AVX1-NEXT:    vcvtsi2sdq %rsi, %xmm2, %xmm0
-; AVX1-NEXT:    vcvtsi2sdq %rdx, %xmm2, %xmm1
-; AVX1-NEXT:    vmovlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
-; AVX1-NEXT:    vcvtsi2sdq %rcx, %xmm2, %xmm1
-; AVX1-NEXT:    vcvtsi2sdq %rax, %xmm2, %xmm2
-; AVX1-NEXT:    vmovlhps {{.*#+}} xmm1 = xmm1[0],xmm2[0]
-; AVX1-NEXT:    vinsertf128 $1, %xmm0, %ymm1, %ymm0
+; AVX1-NEXT:    vroundpd $11, %ymm0, %ymm0
 ; AVX1-NEXT:    retq
   %i = fptosi <4 x double> %x to <4 x i64>
   %r = sitofp <4 x i64> %i to <4 x double>