clarify the required accuracy for OpFMod and OpFRem

OpenCL_Env.txt

@@ -28,6 +28,11 @@ include::config/opencl.asciidoc[]
 // Formatting and links for API functions and enums.
 include::env/dictionary.asciidoc[]
 
+// External Footnotes
+include::env/footnotes.asciidoc[]
+
+<<<
+
 include::copyrights.txt[]
 
 <<<

env/footnotes.asciidoc

@@ -0,0 +1,16 @@
+// Copyright 2023 The Khronos Group. This work is licensed under a
+// Creative Commons Attribution 4.0 International License; see
+// http://creativecommons.org/licenses/by/4.0/
+
+// Please keep footnotes in alphabetical order!
+
+// Note: Follows the suggested syntax from:
+// https://github.com/asciidoctor/asciidoctor-pdf/issues/1397
+
+:fn-opfrem-opfmod: pass:n[ \
+The *OpFRem* and *OpFMod* instructions use cheap approximations of remainder, and the error can be large due to the discontinuity in *trunc*() and *floor*(). This can produce mathematically unexpected results in some cases, such as *OpFMod*(x,x) computing x rather than 0, and can also cause the result to have a different sign than the infinitely precise result. \
+]
+
+:fn-type-min: pass:n[ \
+Here `TYPE_MIN` and `TYPE_MIN_EXP` should be substituted by constants appropriate to the floating-point type under consideration, such as `FLT_MIN` and `FLT_MIN_EXP` for float. \
+]

env/numerical_compliance.asciidoc

@@ -198,6 +198,16 @@ devices given as ULP values.
 | \<= 2.5 ulp
 | Correctly rounded
 
+| *OpFRem*(x, y)
+| Derived from x - y * *trunc*(x/y) footnote:opfrem-opfmod[{fn-opfrem-opfmod}]
+| Derived from x - y * *trunc*(x/y) footnote:opfrem-opfmod[]
+| Derived from x - y * *trunc*(x/y) footnote:opfrem-opfmod[]
+
+| *OpFMod*(x, y)
+| Derived from x - y * *floor*(x/y) footnote:opfrem-opfmod[]
+| Derived from x - y * *floor*(x/y) footnote:opfrem-opfmod[]
+| Derived from x - y * *floor*(x/y) footnote:opfrem-opfmod[]
+
 | *OpExtInst* *acos*
 | \<= 4 ulp
 | \<= 4 ulp
@@ -1782,6 +1792,4 @@ representable numbers in the range 0 < x < TYPE_MIN and -TYPE_MIN < x < -0.
 They do not include {plusmn}0.
 A non-zero number is said to be sub-normal before rounding if, after
 normalization, its radix-2 exponent is less than (TYPE_MIN_EXP - 1).
-footnote:[Here `TYPE_MIN` and `TYPE_MIN_EXP` should be substituted by
-constants appropriate to the floating-point type under consideration, such
-as `FLT_MIN` and `FLT_MIN_EXP` for float.]
+footnote:[{fn-type-min}]