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Further Implement Power of Two Optimization

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This commit is contained in:
Nicholas Thompson 2024-01-23 12:03:50 -05:00
parent 971e37ff7e
commit 9dccd5dce1
3 changed files with 354 additions and 189 deletions
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261
library/core/src/num/int_macros.rs
View File

@ -901,26 +901,59 @@ macro_rules! int_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
if exp == 0 {
return Some(1);
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = try_opt!(acc.checked_mul(base));
// SAFETY: This path has the same behavior as the other.
if unsafe { intrinsics::is_val_statically_known(self) }
&& self.unsigned_abs().is_power_of_two()
{
if self == 1 { // Avoid divide by zero
return Some(1);
}
exp /= 2;
base = try_opt!(base.checked_mul(base));
if self == -1 { // Avoid divide by zero
return Some(if exp & 1 != 0 { -1 } else { 1 });
}
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self.wrapping_abs()) as u32 };
if exp > Self::BITS / power_used { return None; } // Division of constants is free
// SAFETY: exp <= Self::BITS / power_used
let res = unsafe { intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
)};
// LLVM doesn't always optimize out the checks
// at the ir level.
let sign = self.is_negative() && exp & 1 != 0;
if !sign && res == Self::MIN {
None
} else if sign {
Some(res.wrapping_neg())
} else {
Some(res)
}
} else {
if exp == 0 {
return Some(1);
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = try_opt!(acc.checked_mul(base));
}
exp /= 2;
base = try_opt!(base.checked_mul(base));
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.checked_mul(base)
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.checked_mul(base)
}
/// Returns the square root of the number, rounded down.
@ -1537,27 +1570,58 @@ macro_rules! int_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
pub const fn wrapping_pow(self, mut exp: u32) -> Self {
if exp == 0 {
return 1;
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = acc.wrapping_mul(base);
// SAFETY: This path has the same behavior as the other.
if unsafe { intrinsics::is_val_statically_known(self) }
&& self.unsigned_abs().is_power_of_two()
{
if self == 1 { // Avoid divide by zero
return 1;
}
exp /= 2;
base = base.wrapping_mul(base);
}
if self == -1 { // Avoid divide by zero
return if exp & 1 != 0 { -1 } else { 1 };
}
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self.wrapping_abs()) as u32 };
if exp > Self::BITS / power_used { return 0; } // Division of constants is free
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.wrapping_mul(base)
// SAFETY: exp <= Self::BITS / power_used
let res = unsafe { intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
)};
// LLVM doesn't always optimize out the checks
// at the ir level.
let sign = self.is_negative() && exp & 1 != 0;
if sign {
res.wrapping_neg()
} else {
res
}
} else {
if exp == 0 {
return 1;
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = acc.wrapping_mul(base);
}
exp /= 2;
base = base.wrapping_mul(base);
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.wrapping_mul(base)
}
}
/// Calculates `self` + `rhs`
@ -2039,36 +2103,68 @@ macro_rules! int_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
if exp == 0 {
return (1,false);
}
let mut base = self;
let mut acc: Self = 1;
let mut overflown = false;
// Scratch space for storing results of overflowing_mul.
let mut r;
// SAFETY: This path has the same behavior as the other.
if unsafe { intrinsics::is_val_statically_known(self) }
&& self.unsigned_abs().is_power_of_two()
{
if self == 1 { // Avoid divide by zero
return (1, false);
}
if self == -1 { // Avoid divide by zero
return (if exp & 1 != 0 { -1 } else { 1 }, false);
}
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self.wrapping_abs()) as u32 };
if exp > Self::BITS / power_used { return (0, true); } // Division of constants is free
while exp > 1 {
if (exp & 1) == 1 {
r = acc.overflowing_mul(base);
acc = r.0;
// SAFETY: exp <= Self::BITS / power_used
let res = unsafe { intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
)};
// LLVM doesn't always optimize out the checks
// at the ir level.
let sign = self.is_negative() && exp & 1 != 0;
let overflow = res == Self::MIN;
if sign {
(res.wrapping_neg(), overflow)
} else {
(res, overflow)
}
} else {
if exp == 0 {
return (1,false);
}
let mut base = self;
let mut acc: Self = 1;
let mut overflown = false;
// Scratch space for storing results of overflowing_mul.
let mut r;
while exp > 1 {
if (exp & 1) == 1 {
r = acc.overflowing_mul(base);
acc = r.0;
overflown |= r.1;
}
exp /= 2;
r = base.overflowing_mul(base);
base = r.0;
overflown |= r.1;
}
exp /= 2;
r = base.overflowing_mul(base);
base = r.0;
overflown |= r.1;
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
r = acc.overflowing_mul(base);
r.1 |= overflown;
r
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
r = acc.overflowing_mul(base);
r.1 |= overflown;
r
}
}
/// Raises self to the power of `exp`, using exponentiation by squaring.
@ -2086,30 +2182,47 @@ macro_rules! int_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
#[rustc_inherit_overflow_checks]
#[rustc_allow_const_fn_unstable(is_val_statically_known)]
#[track_caller] // Hides the hackish overflow check for powers of two.
pub const fn pow(self, mut exp: u32) -> Self {
// SAFETY: This path has the same behavior as the other.
if unsafe { intrinsics::is_val_statically_known(self) }
&& self > 0
&& (self & (self - 1) == 0)
&& self.unsigned_abs().is_power_of_two()
{
let power_used = match self.checked_ilog2() {
Some(v) => v,
// SAFETY: We just checked this is a power of two. and above zero.
None => unsafe { core::hint::unreachable_unchecked() },
};
// So it panics. Have to use `overflowing_mul` to efficiently set the
// result to 0 if not.
#[cfg(debug_assertions)]
{
_ = power_used * exp;
if self == 1 { // Avoid divide by zero
return 1;
}
if self == -1 { // Avoid divide by zero
return if exp & 1 != 0 { -1 } else { 1 };
}
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self.wrapping_abs()) as u32 };
if exp > Self::BITS / power_used { // Division of constants is free
#[allow(arithmetic_overflow)]
return Self::MAX * Self::MAX * 0;
}
// SAFETY: exp <= Self::BITS / power_used
let res = unsafe { intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
)};
// LLVM doesn't always optimize out the checks
// at the ir level.
let sign = self.is_negative() && exp & 1 != 0;
#[allow(arithmetic_overflow)]
if !sign && res == Self::MIN {
// So it panics.
_ = Self::MAX * Self::MAX;
}
if sign {
res.wrapping_neg()
} else {
res
}
let (num_shl, overflowed) = power_used.overflowing_mul(exp);
let fine = !overflowed
& (num_shl < (mem::size_of::<Self>() * 8) as u32);
(1 << num_shl) * fine as Self
} else {
if exp == 0 {
return 1;

217
library/core/src/num/uint_macros.rs
View File

@ -1005,28 +1005,49 @@ macro_rules! uint_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
pub const fn checked_pow(self, mut exp: u32) -> Option<Self> {
if exp == 0 {
return Some(1);
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = try_opt!(acc.checked_mul(base));
// SAFETY: This path has the same behavior as the other.
if unsafe { intrinsics::is_val_statically_known(self) }
&& self.is_power_of_two()
{
if self == 1 { // Avoid divide by zero
return Some(1);
}
exp /= 2;
base = try_opt!(base.checked_mul(base));
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self) as u32 };
if exp > Self::BITS / power_used { return None; } // Division of constants is free
// SAFETY: exp <= Self::BITS / power_used
unsafe { Some(intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
)) }
// LLVM doesn't always optimize out the checks
// at the ir level.
} else {
if exp == 0 {
return Some(1);
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = try_opt!(acc.checked_mul(base));
}
exp /= 2;
base = try_opt!(base.checked_mul(base));
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.checked_mul(base)
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.checked_mul(base)
}
/// Saturating integer addition. Computes `self + rhs`, saturating at
@ -1475,27 +1496,48 @@ macro_rules! uint_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
pub const fn wrapping_pow(self, mut exp: u32) -> Self {
if exp == 0 {
return 1;
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = acc.wrapping_mul(base);
// SAFETY: This path has the same behavior as the other.
if unsafe { intrinsics::is_val_statically_known(self) }
&& self.is_power_of_two()
{
if self == 1 { // Avoid divide by zero
return 1;
}
exp /= 2;
base = base.wrapping_mul(base);
}
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self) as u32 };
if exp > Self::BITS / power_used { return 0; } // Division of constants is free
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.wrapping_mul(base)
// SAFETY: exp <= Self::BITS / power_used
unsafe { intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
)}
// LLVM doesn't always optimize out the checks
// at the ir level.
} else {
if exp == 0 {
return 1;
}
let mut base = self;
let mut acc: Self = 1;
while exp > 1 {
if (exp & 1) == 1 {
acc = acc.wrapping_mul(base);
}
exp /= 2;
base = base.wrapping_mul(base);
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
acc.wrapping_mul(base)
}
}
/// Calculates `self` + `rhs`
@ -1925,37 +1967,58 @@ macro_rules! uint_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
pub const fn overflowing_pow(self, mut exp: u32) -> (Self, bool) {
if exp == 0{
return (1,false);
}
let mut base = self;
let mut acc: Self = 1;
let mut overflown = false;
// Scratch space for storing results of overflowing_mul.
let mut r;
// SAFETY: This path has the same behavior as the other.
if unsafe { intrinsics::is_val_statically_known(self) }
&& self.is_power_of_two()
{
if self == 1 { // Avoid divide by zero
return (1, false);
}
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self) as u32 };
if exp > Self::BITS / power_used { return (0, true); } // Division of constants is free
while exp > 1 {
if (exp & 1) == 1 {
r = acc.overflowing_mul(base);
acc = r.0;
// SAFETY: exp <= Self::BITS / power_used
unsafe { (intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
), false) }
// LLVM doesn't always optimize out the checks
// at the ir level.
} else {
if exp == 0{
return (1,false);
}
let mut base = self;
let mut acc: Self = 1;
let mut overflown = false;
// Scratch space for storing results of overflowing_mul.
let mut r;
while exp > 1 {
if (exp & 1) == 1 {
r = acc.overflowing_mul(base);
acc = r.0;
overflown |= r.1;
}
exp /= 2;
r = base.overflowing_mul(base);
base = r.0;
overflown |= r.1;
}
exp /= 2;
r = base.overflowing_mul(base);
base = r.0;
overflown |= r.1;
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
r = acc.overflowing_mul(base);
r.1 |= overflown;
r
}
// since exp!=0, finally the exp must be 1.
// Deal with the final bit of the exponent separately, since
// squaring the base afterwards is not necessary and may cause a
// needless overflow.
r = acc.overflowing_mul(base);
r.1 |= overflown;
r
}
/// Raises self to the power of `exp`, using exponentiation by squaring.
@ -1971,9 +2034,10 @@ macro_rules! uint_impl {
#[rustc_const_stable(feature = "const_int_pow", since = "1.50.0")]
#[must_use = "this returns the result of the operation, \
without modifying the original"]
#[rustc_allow_const_fn_unstable(is_val_statically_known, const_int_unchecked_arith)]
#[inline]
#[rustc_inherit_overflow_checks]
#[rustc_allow_const_fn_unstable(is_val_statically_known)]
#[track_caller] // Hides the hackish overflow check for powers of two.
pub const fn pow(self, mut exp: u32) -> Self {
// LLVM now knows that `self` is a constant value, but not a
// constant in Rust. This allows us to compute the power used at
@ -1990,22 +2054,23 @@ macro_rules! uint_impl {
if unsafe { intrinsics::is_val_statically_known(self) }
&& self.is_power_of_two()
{
let power_used = match self.checked_ilog2() {
Some(v) => v,
// SAFETY: We just checked this is a power of two. `0` is not a
// power of two.
None => unsafe { core::hint::unreachable_unchecked() },
};
// So it panics. Have to use `overflowing_mul` to efficiently set the
// result to 0 if not.
#[cfg(debug_assertions)]
{
_ = power_used * exp;
if self == 1 { // Avoid divide by zero
return 1;
}
let (num_shl, overflowed) = power_used.overflowing_mul(exp);
let fine = !overflowed
& (num_shl < (mem::size_of::<Self>() * 8) as u32);
(1 << num_shl) * fine as Self
// SAFETY: We just checked this is a power of two. and above zero.
let power_used = unsafe { intrinsics::cttz_nonzero(self) as u32 };
if exp > Self::BITS / power_used { // Division of constants is free
#[allow(arithmetic_overflow)]
return Self::MAX * Self::MAX * 0;
}
// SAFETY: exp <= Self::BITS / power_used
unsafe { intrinsics::unchecked_shl(
1 as Self,
intrinsics::unchecked_mul(power_used, exp) as Self
)}
// LLVM doesn't always optimize out the checks
// at the ir level.
} else {
if exp == 0 {
return 1;

65
tests/codegen/pow_of_two.rs
View File

@ -1,68 +1,55 @@
// #[cfg(bootstrap)]
// ignore-stage1
// compile-flags: --crate-type=lib -Zmerge-functions=disabled
// compile-flags: --crate-type=lib -Zmerge-functions=disabled -O -C overflow-checks=false
// CHECK-LABEL: @a(
#[no_mangle]
pub fn a(exp: u32) -> u64 {
// CHECK: %[[R:.+]] = and i32 %exp, 63
// CHECK: %[[R:.+]] = zext i32 %[[R:.+]] to i64
// CHECK: %[[R:.+]] = shl nuw i64 %[[R:.+]].i, %[[R:.+]]
// CHECK: ret i64 %[[R:.+]]
// CHECK: %{{[^ ]+}} = icmp ugt i32 %exp, 64
// CHECK: %{{[^ ]+}} = zext i32 %exp to i64
// CHECK: %{{[^ ]+}} = shl nuw i64 {{[^ ]+}}, %{{[^ ]+}}
// CHECK: ret i64 %{{[^ ]+}}
2u64.pow(exp)
}
// CHECK-LABEL: @b(
#[no_mangle]
pub fn b(exp: u32) -> i64 {
// CHECK: %[[R:.+]] = and i32 %exp, 63
// CHECK: %[[R:.+]] = zext i32 %[[R:.+]] to i64
// CHECK: %[[R:.+]] = shl nuw i64 %[[R:.+]].i, %[[R:.+]]
// CHECK: ret i64 %[[R:.+]]
// CHECK: %{{[^ ]+}} = icmp ugt i32 %exp, 64
// CHECK: %{{[^ ]+}} = zext i32 %exp to i64
// CHECK: %{{[^ ]+}} = shl nuw i64 {{[^ ]+}}, %{{[^ ]+}}
// CHECK: ret i64 %{{[^ ]+}}
2i64.pow(exp)
}
// CHECK-LABEL: @c(
#[no_mangle]
pub fn c(exp: u32) -> u32 {
// CHECK: %[[R:.+]].0.i = shl i32 %exp, 1
// CHECK: %[[R:.+]].1.i = icmp sgt i32 %exp, -1
// CHECK: %[[R:.+]].i = icmp ult i32 %[[R:.+]].0.i, 32
// CHECK: %fine.i = and i1 %[[R:.+]].1.i, %[[R:.+]].i
// CHECK: %0 = and i32 %[[R:.+]].0.i, 30
// CHECK: %[[R:.+]].i = zext i1 %fine.i to i32
// CHECK: %[[R:.+]] = shl nuw nsw i32 %[[R:.+]].i, %0
// CHECK: ret i32 %[[R:.+]]
// CHECK: %{{[^ ]+}} = icmp ugt i32 %exp, 16
// CHECK: %{{[^ ]+}} = shl nuw nsw i32 %exp, 1
// CHECK: %{{[^ ]+}} = shl nuw i32 1, %{{[^ ]+}}
// CHECK: %{{[^ ]+}} = select i1 %{{[^ ]+}}, i32 0, i32 %{{[^ ]+}}
// CHECK: ret i32 %{{[^ ]+}}
4u32.pow(exp)
}
// CHECK-LABEL: @d(
#[no_mangle]
pub fn d(exp: u32) -> u32 {
// CHECK: tail call { i32, i1 } @llvm.umul.with.overflow.i32(i32 %exp, i32 5)
// CHECK: %[[R:.+]].0.i = extractvalue { i32, i1 } %[[R:.+]], 0
// CHECK: %[[R:.+]].1.i = extractvalue { i32, i1 } %[[R:.+]], 1
// CHECK: %[[R:.+]].i = xor i1 %[[R:.+]].1.i, true
// CHECK: %[[R:.+]].i = icmp ult i32 %[[R:.+]].0.i, 32
// CHECK: %fine.i = and i1 %[[R:.+]].i, %[[R:.+]].i
// CHECK: %[[R:.+]] = and i32 %[[R:.+]].0.i, 31
// CHECK: %[[R:.+]].i = zext i1 %fine.i to i32
// CHECK: %[[R:.+]] = shl nuw i32 %[[R:.+]].i, %1
// CHECK: ret i32 %[[R:.+]]
// CHECK: %{{[^ ]+}} = icmp ugt i32 %exp, 6
// CHECK: %{{[^ ]+}} = mul nuw nsw i32 %exp, 5
// CHECK: %{{[^ ]+}} = shl nuw nsw i32 1, %{{[^ ]+}}
// CHECK: %{{[^ ]+}} = select i1 {{[^ ]+}}, i32 0, i32 %{{[^ ]+}}
// CHECK: ret i32 %{{[^ ]+}}
32u32.pow(exp)
}
// CHECK-LABEL: @e(
#[no_mangle]
pub fn e(exp: u32) -> i32 {
// CHECK: tail call { i32, i1 } @llvm.umul.with.overflow.i32(i32 %exp, i32 5)
// CHECK: %[[R:.+]].0.i = extractvalue { i32, i1 } %[[R:.+]], 0
// CHECK: %[[R:.+]].i = icmp ult i32 %[[R:.+]].0.i, 32
// CHECK: %[[R:.+]].1.i = extractvalue { i32, i1 } %[[R:.+]], 1
// CHECK: %[[R:.+]].i = xor i1 %[[R:.+]].1.i, true
// CHECK: %fine.i = and i1 %[[R:.+]].i, %[[R:.+]].i
// CHECK: %[[R:.+]].i = zext i1 %fine.i to i32
// CHECK: %[[R:.+]] = and i32 %[[R:.+]].0.i, 31
// CHECK: %[[R:.+]] = shl nuw i32 %[[R:.+]].i, %1
// CHECK: ret i32 %[[R:.+]]
// CHECK: %{{[^ ]+}} = icmp ugt i32 %exp, 6
// CHECK: %{{[^ ]+}} = mul nuw {{(nsw )?}}i32 %exp, 5
// CHECK: %{{[^ ]+}} = shl nuw {{(nsw )?}}i32 1, %{{[^ ]+}}
// CHECK: %{{[^ ]+}} = select i1 {{[^ ]+}}, i32 0, i32 %{{[^ ]+}}
// CHECK: ret i32 %{{[^ ]+}}
32i32.pow(exp)
}
// note: d and e are expected to yield the same IR