From 41bbd829d1cdb649f19ab493bde39ce031cc3fb1 Mon Sep 17 00:00:00 2001
From: evoskuil <eric@voskuil.org>
Date: Fri, 20 Feb 2026 15:31:21 -0500
Subject: [PATCH 1/2] Add constexpr Float power(Float base, Exponent exponent).

---
 include/bitcoin/system/impl/math/power.ipp | 17 +++++++++++++++++
 include/bitcoin/system/math/power.hpp      |  6 ++++++
 test/math/power.cpp                        | 17 ++++++++++++++++-
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/include/bitcoin/system/impl/math/power.ipp b/include/bitcoin/system/impl/math/power.ipp
index 967c03f6fc..4245486bde 100644
--- a/include/bitcoin/system/impl/math/power.ipp
+++ b/include/bitcoin/system/impl/math/power.ipp
@@ -112,6 +112,23 @@ constexpr Value power2(Exponent exponent) NOEXCEPT
         possible_narrow_and_sign_cast<unsigned>(exponent));
 }
 
+template <typename Float, typename Exponent,
+    if_floating_point<Float>,
+    if_unsigned_integer<Exponent>>
+constexpr Float power(Float base, Exponent exponent) NOEXCEPT
+{
+    // 0^0 is undefined, return 0.
+    if ((base == 0.0) && is_zero(exponent))
+        return 0.0;
+
+    Float product{ 1.0 };
+    while (exponent-- > 0u)
+        if ((product *= base) == 0.0)
+            break;
+
+    return product;
+}
+
 } // namespace system
 } // namespace libbitcoin
 
diff --git a/include/bitcoin/system/math/power.hpp b/include/bitcoin/system/math/power.hpp
index 59652aa2a5..52eed75ab6 100644
--- a/include/bitcoin/system/math/power.hpp
+++ b/include/bitcoin/system/math/power.hpp
@@ -54,6 +54,12 @@ template <typename Value = size_t, typename Exponent,
     if_unsigned_integer<Exponent> = true>
 constexpr Value power2(Exponent exponent) NOEXCEPT;
 
+/// Floating point constexpr optimization for integer exponent.
+template <typename Float, typename Exponent,
+    if_floating_point<Float> = true,
+    if_unsigned_integer<Exponent> = true>
+constexpr Float power(Float base, Exponent exponent) NOEXCEPT;
+
 } // namespace system
 } // namespace libbitcoin
 
diff --git a/test/math/power.cpp b/test/math/power.cpp
index af595a308e..bf7c7ebb08 100644
--- a/test/math/power.cpp
+++ b/test/math/power.cpp
@@ -66,10 +66,25 @@ static_assert(power<3, size_t>(0u) == 1u);
 // uint256_t
 static_assert(power<2u, uint256_t>(10u) == 1024u);
 
-// uintx is not constexpr.
+
+// floating point
+static_assert(is_same_type<decltype(power(0.0f, 0u)), float>);
+static_assert(is_same_type<decltype(power(0.0, 0u)), double>);
+
+static_assert(power(0.0f, 0u) == 0.0f);
+static_assert(power(0.0, 0u) == 0.0);
+static_assert(power(1.0, 0u) == 1.0);
+static_assert(power(1.0, 1u) == 1.0);
+static_assert(power(2.0, 1u) == 2.0);
+static_assert(power(2.0, 2u) == 4.0);
+static_assert(power(3.0, 3u) == 27.0);
+
+// Actually 311.1696 but this is the floating point representation.
+static_assert(power(4.2, 4u) == 311.16960000000006);
 
 BOOST_AUTO_TEST_SUITE(power_tests)
 
+// uintx is not constexpr.
 BOOST_AUTO_TEST_CASE(power_uintx_tests)
 {
     BOOST_REQUIRE(true);

From 110c89dd9e160a7332ec45c07a5e2a7791270766 Mon Sep 17 00:00:00 2001
From: evoskuil <eric@voskuil.org>
Date: Fri, 20 Feb 2026 16:11:25 -0500
Subject: [PATCH 2/2] Style (normalize power implementations).

---
 include/bitcoin/system/impl/math/power.ipp | 17 +++++------------
 test/math/power.cpp                        |  4 +---
 2 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/include/bitcoin/system/impl/math/power.ipp b/include/bitcoin/system/impl/math/power.ipp
index 4245486bde..cf3f36f79e 100644
--- a/include/bitcoin/system/impl/math/power.ipp
+++ b/include/bitcoin/system/impl/math/power.ipp
@@ -33,6 +33,7 @@ namespace system {
 
 // Called by bc::base85 (for number coding).
 // Called by wallet::electrum_v1 (for number coding).
+// Overflow is allowed behavior as this models a mathematical operator.
 template <typename Value, typename Base, typename Exponent,
     if_integer<Value> = true,
     if_integer<Base> = true,
@@ -42,19 +43,11 @@ constexpr Value power_(Base base, Exponent exponent) NOEXCEPT
     if (is_power_overflow(base, exponent))
         return 0;
 
-    if (is_zero(exponent))
-        return 1;
-
-    auto value = possible_narrow_and_sign_cast<Value>(base);
-
-    // Overflow is allowed behavior as this models a mathematical operator.
-    BC_PUSH_WARNING(NARROWING_CONVERSION)
-    BC_PUSH_WARNING(SIZE_NARROWING_CONVERSION)
-    while (--exponent > 0u) { value *= base; }
-    BC_POP_WARNING()
-    BC_POP_WARNING()
+    Value product{ 1 };
+    while (exponent-- > 0u)
+        product *= possible_narrow_and_sign_cast<Value>(base);
 
-    return value;
+    return product;
 }
 
 // published
diff --git a/test/math/power.cpp b/test/math/power.cpp
index bf7c7ebb08..8b74018e6f 100644
--- a/test/math/power.cpp
+++ b/test/math/power.cpp
@@ -37,7 +37,6 @@ static_assert(power(3,   0u) == 1u);
 static_assert(power(3u,  0u) == 1u);
 static_assert(power(3,  10u) == 0xe6a9_size);
 static_assert(power(3u, 10u) == 0xe6a9_size);
-static_assert(power<uint16_t>(3, 11u) == 0xb3fb_u16);
 
 static_assert(power(-1, 0u) == 1u);
 static_assert(power(-1, 1u) == 1_nsize);
@@ -45,7 +44,6 @@ static_assert(power(-1, 1u) == 1_nsize);
 static_assert(power(-3,  0u) == 1u);
 static_assert(power(-3,  1u) == 3_nsize);
 static_assert(power(-3, 10u) == 0xe6a9_size);
-static_assert(power<uint16_t>(-3, 11u) == 0x4c05_u16);
 
 // power2
 static_assert(power2(0u) == 1u);
@@ -53,7 +51,7 @@ static_assert(power2(0u) == 1u);
 static_assert(power2(1u) == 2u);
 static_assert(power2(1u) == 2u);
 static_assert(power2<uint16_t>(15u) == 0b1000'0000'0000'0000_u16);
-static_assert(power2<uint16_t>(16u) == 0_u16);
+static_assert(power2<uint16_t>(16u) == 0_u16); // overflow
 
 // power<>
 static_assert(power<0>(16u) == power(0u, 16u));