diff --git a/llvm/test/Transforms/InstCombine/pow_fp_int16.ll b/llvm/test/Transforms/InstCombine/pow_fp_int16.ll
new file mode 100644
index 00000000000000..94e6ef2885d4d7
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/pow_fp_int16.ll
@@ -0,0 +1,461 @@
+; RUN: opt -mtriple msp430 -instcombine -S < %s | FileCheck %s
+
+; Test case was copied from pow_fp_int.ll but adjusted for 16-bit int.
+; Assuming that we can't generate test checks for the same reason (PR42740).
+;
+; FIXME: All calls to powi.f32 using i32 for the exponent is faulty. The
+;        RT lib functions expects an "C type int" which maps to i16 for
+;        some targets such as msp430.
+
+define double @pow_sitofp_const_base_fast(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_const_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_fast(i15 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i15 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i15 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_double_const_base_fast(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_double_const_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn double @llvm.powi.f64(double 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %subfp = sitofp i16 %x to double
+  %pow = tail call afn double @llvm.pow.f64(double 7.000000e+00, double %subfp)
+  ret double %pow
+}
+
+define double @pow_uitofp_double_const_base_fast(i15 %x) {
+; CHECK-LABEL: @pow_uitofp_double_const_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i15 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn double @llvm.powi.f64(double 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %subfp = uitofp i15 %x to double
+  %pow = tail call afn double @llvm.pow.f64(double 7.000000e+00, double %subfp)
+  ret double %pow
+}
+
+define double @pow_sitofp_double_const_base_2_fast(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_double_const_base_2_fast(
+; CHECK-NEXT:    [[LDEXPF:%.*]] = call afn float @ldexpf(float 1.000000e+00, i16 [[X:%.*]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[LDEXPF]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 2.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_double_const_base_power_of_2_fast(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_double_const_base_power_of_2_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = sitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[MUL:%.*]] = fmul afn float [[SUBFP]], 4.000000e+00
+; CHECK-NEXT:    [[EXP2:%.*]] = call afn float @llvm.exp2.f32(float [[MUL]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 16.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_2_fast(i15 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_2_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i15 [[X:%.*]] to i16
+; CHECK-NEXT:    [[LDEXPF:%.*]] = call afn float @ldexpf(float 1.000000e+00, i16 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[LDEXPF]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i15 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 2.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_power_of_2_fast(i15 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_power_of_2_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i15 [[X:%.*]] to float
+; CHECK-NEXT:    [[MUL:%.*]] = fmul afn float [[SUBFP]], 4.000000e+00
+; CHECK-NEXT:    [[EXP2:%.*]] = call afn float @llvm.exp2.f32(float [[MUL]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i15 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 16.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_float_base_fast(float %base, i16 %x) {
+; CHECK-LABEL: @pow_sitofp_float_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float [[BASE:%.*]], i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float %base, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_float_base_fast(float %base, i15 %x) {
+; CHECK-LABEL: @pow_uitofp_float_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i15 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float [[BASE:%.*]], i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i15 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float %base, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_double_base_fast(double %base, i16 %x) {
+; CHECK-LABEL: @pow_sitofp_double_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn double @llvm.powi.f64(double [[BASE:%.*]], i32 [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %subfp = sitofp i16 %x to double
+  %res = tail call afn double @llvm.pow.f64(double %base, double %subfp)
+  ret double %res
+}
+
+define double @pow_uitofp_double_base_fast(double %base, i15 %x) {
+; CHECK-LABEL: @pow_uitofp_double_base_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i15 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn double @llvm.powi.f64(double [[BASE:%.*]], i32 [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %subfp = uitofp i15 %x to double
+  %res = tail call afn double @llvm.pow.f64(double %base, double %subfp)
+  ret double %res
+}
+
+define double @pow_sitofp_const_base_fast_i8(i8 %x) {
+; CHECK-LABEL: @pow_sitofp_const_base_fast_i8(
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i8 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i8 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_const_base_fast_i16(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_const_base_fast_i16(
+; CHECK-NEXT:    [[TMP1:%.*]] = sext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+
+define double @pow_uitofp_const_base_fast_i8(i8 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_fast_i8(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i8 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i8 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_afn_i16(i16 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_afn_i16(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call afn float @llvm.powi.f32(float 7.000000e+00, i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call afn float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @powf_exp_const_int_fast(double %base) {
+; CHECK-LABEL: @powf_exp_const_int_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = call fast double @llvm.powi.f64(double [[BASE:%.*]], i32 40)
+; CHECK-NEXT:    ret double [[TMP1]]
+;
+  %res = tail call fast double @llvm.pow.f64(double %base, double 4.000000e+01)
+  ret double %res
+}
+
+define double @powf_exp_const2_int_fast(double %base) {
+; CHECK-LABEL: @powf_exp_const2_int_fast(
+; CHECK-NEXT:    [[TMP1:%.*]] = call fast double @llvm.powi.f64(double [[BASE:%.*]], i32 -40)
+; CHECK-NEXT:    ret double [[TMP1]]
+;
+  %res = tail call fast double @llvm.pow.f64(double %base, double -4.000000e+01)
+  ret double %res
+}
+
+; Negative tests
+
+define double @pow_uitofp_const_base_fast_i16(i16 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_fast_i16(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[MUL:%.*]] = fmul fast float [[SUBFP]], 0x4006757{{.*}}
+; CHECK-NEXT:    [[EXP2:%.*]] = call fast float @llvm.exp2.f32(float [[MUL]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call fast float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_2_fast_i16(i16 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_2_fast_i16(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[EXP2:%.*]] = call fast float @llvm.exp2.f32(float [[SUBFP]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call fast float @llvm.pow.f32(float 2.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_power_of_2_fast_i16(i16 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_power_of_2_fast_i16(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[MUL:%.*]] = fmul fast float [[SUBFP]], 4.000000e+00
+; CHECK-NEXT:    [[EXP2:%.*]] = call fast float @llvm.exp2.f32(float [[MUL]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call fast float @llvm.pow.f32(float 16.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_float_base_fast_i16(float %base, i16 %x) {
+; CHECK-LABEL: @pow_uitofp_float_base_fast_i16(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast float @llvm.powi.f32(float [[BASE:%.*]], i32 [[TMP1]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[TMP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call fast float @llvm.pow.f32(float %base, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_double_base_fast_i16(double %base, i16 %x) {
+; CHECK-LABEL: @pow_uitofp_double_base_fast_i16(
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i16 [[X:%.*]] to i32
+; CHECK-NEXT:    [[TMP2:%.*]] = call fast double @llvm.powi.f64(double [[BASE:%.*]], i32 [[TMP1]])
+; CHECK-NEXT:    ret double [[TMP2]]
+;
+  %subfp = uitofp i16 %x to double
+  %res = tail call fast double @llvm.pow.f64(double %base, double %subfp)
+  ret double %res
+}
+
+define double @pow_sitofp_const_base_no_fast(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_const_base_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = sitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[POW:%.*]] = tail call float @llvm.pow.f32(float 7.000000e+00, float [[SUBFP]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[POW]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_no_fast(i16 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[POW:%.*]] = tail call float @llvm.pow.f32(float 7.000000e+00, float [[SUBFP]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[POW]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float 7.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_const_base_2_no_fast(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_const_base_2_no_fast(
+; CHECK-NEXT:    [[LDEXPF:%.*]] = call float @ldexpf(float 1.000000e+00, i16 [[X:%.*]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[LDEXPF]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float 2.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_const_base_power_of_2_no_fast(i16 %x) {
+; CHECK-LABEL: @pow_sitofp_const_base_power_of_2_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = sitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[MUL:%.*]] = fmul float [[SUBFP]], 4.000000e+00
+; CHECK-NEXT:    [[EXP2:%.*]] = call float @llvm.exp2.f32(float [[MUL]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float 16.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_2_no_fast(i16 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_2_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[EXP2:%.*]] = call float @llvm.exp2.f32(float [[SUBFP]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float 2.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_const_base_power_of_2_no_fast(i16 %x) {
+; CHECK-LABEL: @pow_uitofp_const_base_power_of_2_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[MUL:%.*]] = fmul float [[SUBFP]], 4.000000e+00
+; CHECK-NEXT:    [[EXP2:%.*]] = call float @llvm.exp2.f32(float [[MUL]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[EXP2]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float 16.000000e+00, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_float_base_no_fast(float %base, i16 %x) {
+; CHECK-LABEL: @pow_sitofp_float_base_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = sitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[POW:%.*]] = tail call float @llvm.pow.f32(float [[BASE:%.*]], float [[SUBFP]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[POW]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = sitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float %base, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_uitofp_float_base_no_fast(float %base, i16 %x) {
+; CHECK-LABEL: @pow_uitofp_float_base_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to float
+; CHECK-NEXT:    [[POW:%.*]] = tail call float @llvm.pow.f32(float [[BASE:%.*]], float [[SUBFP]])
+; CHECK-NEXT:    [[RES:%.*]] = fpext float [[POW]] to double
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %subfp = uitofp i16 %x to float
+  %pow = tail call float @llvm.pow.f32(float %base, float %subfp)
+  %res = fpext float %pow to double
+  ret double %res
+}
+
+define double @pow_sitofp_double_base_no_fast(double %base, i16 %x) {
+; CHECK-LABEL: @pow_sitofp_double_base_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = sitofp i16 [[X:%.*]] to double
+; CHECK-NEXT:    [[POW:%.*]] = tail call double @llvm.pow.f64(double [[BASE:%.*]], double [[SUBFP]])
+; CHECK-NEXT:    ret double [[POW]]
+;
+  %subfp = sitofp i16 %x to double
+  %pow = tail call double @llvm.pow.f64(double %base, double %subfp)
+  ret double %pow
+}
+
+define double @pow_uitofp_double_base_no_fast(double %base, i16 %x) {
+; CHECK-LABEL: @pow_uitofp_double_base_no_fast(
+; CHECK-NEXT:    [[SUBFP:%.*]] = uitofp i16 [[X:%.*]] to double
+; CHECK-NEXT:    [[POW:%.*]] = tail call double @llvm.pow.f64(double [[BASE:%.*]], double [[SUBFP]])
+; CHECK-NEXT:    ret double [[POW]]
+;
+  %subfp = uitofp i16 %x to double
+  %pow = tail call double @llvm.pow.f64(double %base, double %subfp)
+  ret double %pow
+}
+
+define double @powf_exp_const_int_no_fast(double %base) {
+; CHECK-LABEL: @powf_exp_const_int_no_fast(
+; CHECK-NEXT:    [[RES:%.*]] = tail call double @llvm.pow.f64(double [[BASE:%.*]], double 4.000000e+01)
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %res = tail call double @llvm.pow.f64(double %base, double 4.000000e+01)
+  ret double %res
+}
+
+define double @powf_exp_const_not_int_fast(double %base) {
+; CHECK-LABEL: @powf_exp_const_not_int_fast(
+; CHECK-NEXT:    [[RES:%.*]] = tail call fast double @llvm.pow.f64(double [[BASE:%.*]], double 3.750000e+01)
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %res = tail call fast double @llvm.pow.f64(double %base, double 3.750000e+01)
+  ret double %res
+}
+
+define double @powf_exp_const_not_int_no_fast(double %base) {
+; CHECK-LABEL: @powf_exp_const_not_int_no_fast(
+; CHECK-NEXT:    [[RES:%.*]] = tail call double @llvm.pow.f64(double [[BASE:%.*]], double 3.750000e+01)
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %res = tail call double @llvm.pow.f64(double %base, double 3.750000e+01)
+  ret double %res
+}
+
+define double @powf_exp_const2_int_no_fast(double %base) {
+; CHECK-LABEL: @powf_exp_const2_int_no_fast(
+; CHECK-NEXT:    [[RES:%.*]] = tail call double @llvm.pow.f64(double [[BASE:%.*]], double -4.000000e+01)
+; CHECK-NEXT:    ret double [[RES]]
+;
+  %res = tail call double @llvm.pow.f64(double %base, double -4.000000e+01)
+  ret double %res
+}
+
+declare float @llvm.pow.f32(float, float)
+declare double @llvm.pow.f64(double, double)