From f8e2c6497bdf71344dd6a978233e32f3f8b901fa Mon Sep 17 00:00:00 2001
From: BIGFERRY999 <bigferry24@gmail.com>
Date: Mon, 12 Oct 2026 22:43:46 +0100
Subject: [PATCH] feat(libc): implement floor

---
 core/libs/prx/libc/src/Math.cpp |  1 +
 core/libs/tests/GuestMath.cpp   | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/core/libs/prx/libc/src/Math.cpp b/core/libs/prx/libc/src/Math.cpp
index 154bfa5ae..9705bb62e 100644
--- a/core/libs/prx/libc/src/Math.cpp
+++ b/core/libs/prx/libc/src/Math.cpp
@@ -200,6 +200,7 @@ double APS5_VABI fabs_nid_postfix(double x) { return std::fabs(x); }
 int APS5_VABI abs_nid_postfix(int x) { return x < 0 ? static_cast<int>(0u - static_cast<unsigned>(x)) : x; }
 double APS5_VABI trunc_nid_postfix(double x) { return std::trunc(x); }
 double APS5_VABI ceil_nid_postfix(double x) { return std::ceil(x); }
+double APS5_VABI floor_nid_postfix(double x) { return std::floor(x); }
 double APS5_VABI fma_nid_postfix(double x, double y, double z) { return std::fma(x, y, z); }
 long double APS5_VABI acosl_nid_postfix(long double x) { return std::acos(x); }
 
diff --git a/core/libs/tests/GuestMath.cpp b/core/libs/tests/GuestMath.cpp
index 103c6e5bd..3931dc388 100644
--- a/core/libs/tests/GuestMath.cpp
+++ b/core/libs/tests/GuestMath.cpp
@@ -34,6 +34,7 @@ double APS5_VABI fabs_nid_postfix(double);
 int APS5_VABI abs_nid_postfix(int);
 double APS5_VABI trunc_nid_postfix(double);
 double APS5_VABI ceil_nid_postfix(double);
+double APS5_VABI floor_nid_postfix(double);
 double APS5_VABI nearbyint_nid_postfix(double);
 double APS5_VABI fma_nid_postfix(double, double, double);
 long double APS5_VABI acosl_nid_postfix(long double);
@@ -146,6 +147,15 @@ static void CheckExactOperations() {
     Require(std::fesetround(FE_DOWNWARD) == 0);
     const bool ceilIgnoresRounding = ceil_nid_postfix(2.2) == 3. && ceil_nid_postfix(-2.7) == -2.;
     Require(std::fesetround(FE_TONEAREST) == 0 && ceilIgnoresRounding);
+    Require(floor_nid_postfix(2.7) == 2. && floor_nid_postfix(-2.2) == -3. && floor_nid_postfix(5.) == 5.);
+    Require(std::bit_cast<std::uint64_t>(floor_nid_postfix(-0.5)) == 0xbff0000000000000ull);
+    Require(std::bit_cast<std::uint64_t>(floor_nid_postfix(-0.)) == 0x8000000000000000ull && floor_nid_postfix(-0x1p-1074) == -1.);
+    Require(std::bit_cast<std::uint64_t>(floor_nid_postfix(0.5)) == 0);
+    Require(floor_nid_postfix(4503599627370495.5) == 4503599627370495. && floor_nid_postfix(-1e300) == -1e300);
+    Require(floor_nid_postfix(INFINITY) == INFINITY && floor_nid_postfix(-INFINITY) == -INFINITY && std::isnan(floor_nid_postfix(nan)));
+    Require(std::fesetround(FE_UPWARD) == 0);
+    const bool floorIgnoresRounding = floor_nid_postfix(2.7) == 2. && floor_nid_postfix(-2.2) == -3.;
+    Require(std::fesetround(FE_TONEAREST) == 0 && floorIgnoresRounding);
     Require(fma_nid_postfix(2., 3., 4.) == 10.);
     volatile double tenth = 0.1;
     Require(fma_nid_postfix(tenth, 10., -1.) == 0x1p-54);