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From 5a93e9a6c82d93970742972e0cf68ef62cb4f313 Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Tue, 26 May 2026 13:12:29 +0100
Subject: [PATCH] ANGLE: skip excess-precision-sensitive roundToNearest
static_asserts on x87
On 32-bit x86 targets with x87 FP (FLT_EVAL_METHOD == 2), constexpr
float/double arithmetic is performed at 80-bit extended precision, so
0.49999997f + 0.5f compares to long-double 0.99999996... != 1.0 and the
static_assert fails. The runtime bias trick remains correct (the result
is still cast back to float and rounded). Skip the compile-time checks
when __FLT_EVAL_METHOD__ != 0.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
Source/ThirdParty/ANGLE/src/common/mathutil.h | 2 ++
1 file changed, 2 insertions(+)
--- a/Source/ThirdParty/ANGLE/src/common/mathutil.h
+++ b/Source/ThirdParty/ANGLE/src/common/mathutil.h
@@ -606,10 +606,12 @@ inline R roundToNearest(T input)
// On armv8, this expression is compiled to a dedicated round-to-nearest instruction
return static_cast<R>(std::round(input));
#else
+#if !defined(__FLT_EVAL_METHOD__) || __FLT_EVAL_METHOD__ == 0
static_assert(0.49999997f < 0.5f);
static_assert(0.49999997f + 0.5f == 1.0f);
static_assert(0.49999999999999994 < 0.5);
static_assert(0.49999999999999994 + 0.5 == 1.0);
+#endif
constexpr T bias = sizeof(T) == 8 ? 0.49999999999999994 : 0.49999997f;
return static_cast<R>(input + (std::is_signed<R>::value ? std::copysign(bias, input) : bias));
#endif
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