diff --git a/llvm/test/CodeGen/X86/isel-fabs-x87.ll b/llvm/test/CodeGen/X86/isel-fabs-x87.ll
new file mode 100644
index 0000000000000..8b846499946cc
--- /dev/null
+++ b/llvm/test/CodeGen/X86/isel-fabs-x87.ll
@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=x86_64-- -mattr=+x87,-sse2,-sse | FileCheck %s --check-prefixes=X64
+; RUN: llc < %s -mtriple=x86_64-- -mattr=+x87,-sse2,-sse -fast-isel -fast-isel-abort=1 | FileCheck %s --check-prefixes=X64
+; RUN: llc < %s -mtriple=i686-- -mattr=+x87,-sse2,-sse | FileCheck %s --check-prefixes=X86
+; RUN: llc < %s -mtriple=i686-- -mattr=+x87,-sse2,-sse -fast-isel -fast-isel-abort=1 | FileCheck %s --check-prefixes=X86
+
+define x86_fp80 @test_x86_fp80_abs(x86_fp80 %arg) {
+; X64-LABEL: test_x86_fp80_abs:
+; X64:       # %bb.0:
+; X64-NEXT:    fldt {{[0-9]+}}(%rsp)
+; X64-NEXT:    fabs
+; X64-NEXT:    retq
+;
+; X86-LABEL: test_x86_fp80_abs:
+; X86:       # %bb.0:
+; X86-NEXT:    fldt {{[0-9]+}}(%esp)
+; X86-NEXT:    fabs
+; X86-NEXT:    retl
+  %abs = tail call x86_fp80 @llvm.fabs.f80(x86_fp80 %arg)
+  ret x86_fp80 %abs
+}
diff --git a/llvm/test/CodeGen/X86/isel-fabs.ll b/llvm/test/CodeGen/X86/isel-fabs.ll
new file mode 100644
index 0000000000000..10bd5799280ad
--- /dev/null
+++ b/llvm/test/CodeGen/X86/isel-fabs.ll
@@ -0,0 +1,50 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=x86_64-- -mattr=-x87 | FileCheck %s --check-prefixes=X64
+; RUN: llc < %s -mtriple=x86_64-- -mattr=-x87 -fast-isel -fast-isel-abort=1 | FileCheck %s --check-prefixes=X64
+; RUN: llc < %s -mtriple=i686-- -mattr=-x87 | FileCheck %s --check-prefixes=X86
+; RUN: llc < %s -mtriple=i686-- -mattr=-x87 -fast-isel -fast-isel-abort=1 | FileCheck %s --check-prefixes=FASTISEL-X86
+
+
+define float @test_float_abs(float %arg) {
+; X64-LABEL: test_float_abs:
+; X64:       # %bb.0:
+; X64-NEXT:    andps {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT:    retq
+;
+; X86-LABEL: test_float_abs:
+; X86:       # %bb.0:
+; X86-NEXT:    movl $2147483647, %eax # imm = 0x7FFFFFFF
+; X86-NEXT:    andl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    retl
+;
+; FASTISEL-X86-LABEL: test_float_abs:
+; FASTISEL-X86:       # %bb.0:
+; FASTISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; FASTISEL-X86-NEXT:    andl $2147483647, %eax # imm = 0x7FFFFFFF
+; FASTISEL-X86-NEXT:    retl
+    %abs = tail call float @llvm.fabs.f32(float %arg)
+    ret float %abs
+}
+
+define double @test_double_abs(double %arg) {
+; X64-LABEL: test_double_abs:
+; X64:       # %bb.0:
+; X64-NEXT:    andps {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %xmm0
+; X64-NEXT:    retq
+;
+; X86-LABEL: test_double_abs:
+; X86:       # %bb.0:
+; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; X86-NEXT:    movl $2147483647, %edx # imm = 0x7FFFFFFF
+; X86-NEXT:    andl {{[0-9]+}}(%esp), %edx
+; X86-NEXT:    retl
+;
+; FASTISEL-X86-LABEL: test_double_abs:
+; FASTISEL-X86:       # %bb.0:
+; FASTISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
+; FASTISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; FASTISEL-X86-NEXT:    andl $2147483647, %edx # imm = 0x7FFFFFFF
+; FASTISEL-X86-NEXT:    retl
+    %abs = tail call double @llvm.fabs.f64(double %arg)
+    ret double %abs
+}