[InstCombine][msp430] Pre-commit test case for @llvm.powi and 16-bit ints

This is a pre-commit of a test case D99439 which is a patch that
updates @llvm.powi to handle different int sizes for the exponent.

Problem is that @llvm.powi is used as an IR construct that maps
to RT libcalls to __powi* functions, and those lib functions depend
on sizeof(int) to use correct type for the exponent.

The test cases show that we use i32 for the powi expenent, which
later would result in wrong type being used in libcalls (miscompile).

But there are also a couple of the negative test cases that show
that we rewrite into using powi when having a uitofp conversion
from i16, which would be wrong when doing the libcall as an
"unsigned int" isn't guaranteed to fit inside the "int" argument
in the called libcall function.

Differential Revision: https://reviews.llvm.org/D102919

diff --git a/llvm/test/Transforms/InstCombine/pow_fp_int16.ll b/llvm/test/Transforms/InstCombine/pow_fp_int16.ll
new file mode 100644 (file)
index 0000000..94e6ef2
--- /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)