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Merge nontrapping-float-to-int proposal into spec (#1143)
See the non-trapping-float-to-int-conversions proposal here: https://github.com/WebAssembly/nontrapping-float-to-int-conversions
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‎document/core/appendix/index-instructions.rst‎

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‎document/core/binary/instructions.rst‎

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@@ -363,6 +363,23 @@ All other numeric instructions are plain opcodes without any immediates.
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\hex{BF} &\Rightarrow& \F64.\REINTERPRET\K{\_}\I64 \\
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\end{array}
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.. _binary-cvtop-trunc-sat:
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The saturating truncation instructions all have a one byte prefix.
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.. math::
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\begin{array}{llclll}
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\production{instruction} & \Binstr &::=& \dots && \phantom{thisshouldbeenough} \\&&|&
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\hex{FC}~\hex{00} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F32\K{\_s} \\ &&|&
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\hex{FC}~\hex{01} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F32\K{\_u} \\ &&|&
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\hex{FC}~\hex{02} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F64\K{\_s} \\ &&|&
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\hex{FC}~\hex{03} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F64\K{\_u} \\ &&|&
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\hex{FC}~\hex{04} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F32\K{\_s} \\ &&|&
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\hex{FC}~\hex{05} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F32\K{\_u} \\ &&|&
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\hex{FC}~\hex{06} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F64\K{\_s} \\ &&|&
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\hex{FC}~\hex{07} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F64\K{\_u} \\
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\end{array}
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.. index:: expression
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pair: binary format; expression

‎document/core/exec/numerics.rst‎

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@@ -1464,6 +1464,62 @@ Conversions
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It is not defined for NaNs, infinities, or values for which the result is out of range.
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.. _op-trunc_u_sat:
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:math:`\truncusat_{M,N}(z)`
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...........................
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* If :math:`z` is a NaN, then return :math:`0`.
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* Else if :math:`z` is negative infinity, then return :math:`0`.
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* Else if :math:`z` is positive infinity, then return :math:`2^N - 1`.
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* Else if :math:`\trunc(z)` is less than :math:`0`, then return :math:`0`.
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* Else if :math:`\trunc(z)` is greater than :math:`2^N - 1`, then return :math:`2^N - 1`.
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* Else, return :math:`\trunc(z)`.
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.. math::
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\begin{array}{lll@{\qquad}l}
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\truncusat_{M,N}(\pm \NAN(n)) &=& 0 \\
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\truncusat_{M,N}(- \infty) &=& 0 \\
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\truncusat_{M,N}(+ \infty) &=& 2^N - 1 \\
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\truncusat_{M,N}(- q) &=& 0 & (\iff \trunc(- q) < 0) \\
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\truncusat_{M,N}(+ q) &=& 2^N - 1 & (\iff \trunc(+ q) > 2^N - 1) \\
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\truncusat_{M,N}(\pm q) &=& \trunc(\pm q) & (otherwise) \\
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\end{array}
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.. _op-trunc_s_sat:
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:math:`\truncssat_{M,N}(z)`
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...........................
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* If :math:`z` is a NaN, then return :math:`0`.
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* Else if :math:`z` is negative infinity, then return :math:`-2^{N-1}`.
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* Else if :math:`z` is positive infinity, then return :math:`2^{N-1} - 1`.
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* Else if :math:`\trunc(z)` is less than :math:`-2^{N-1}`, then return :math:`-2^{N-1}`.
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* Else if :math:`\trunc(z)` is greater than :math:`2^{N-1} - 1`, then return :math:`2^{N-1} - 1`.
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* Else, return :math:`\trunc(z)`.
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.. math::
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\begin{array}{lll@{\qquad}l}
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\truncssat_{M,N}(\pm \NAN(n)) &=& 0 \\
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\truncssat_{M,N}(- \infty) &=& -2^{N-1} \\
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\truncssat_{M,N}(+ \infty) &=& 2^{N-1}-1 \\
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\truncssat_{M,N}(- q) &=& -2^{N-1} & (\iff \trunc(- q) < -2^{N-1}) \\
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\truncssat_{M,N}(+ q) &=& 2^{N-1} - 1 & (\iff \trunc(+ q) > 2^{N-1} - 1) \\
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\truncssat_{M,N}(\pm q) &=& \trunc(\pm q) & (otherwise) \\
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\end{array}
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.. _op-promote:
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:math:`\promote_{M,N}(z)`

‎document/core/syntax/instructions.rst‎

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@@ -67,6 +67,7 @@ These operations closely match respective operations available in hardware.
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\K{i32.}\WRAP\K{\_i64} ~|~
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\K{i64.}\EXTEND\K{\_i32}\K{\_}\sx ~|~
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\K{i}\X{nn}\K{.}\TRUNC\K{\_f}\X{mm}\K{\_}\sx \\&&|&
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\K{i}\X{nn}\K{.}\TRUNC\K{\_sat\_f}\X{mm}\K{\_}\sx \\&&|&
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\K{f32.}\DEMOTE\K{\_f64} ~|~
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\K{f64.}\PROMOTE\K{\_f32} ~|~
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\K{f}\X{nn}\K{.}\CONVERT\K{\_i}\X{mm}\K{\_}\sx \\&&|&
@@ -160,6 +161,7 @@ Occasionally, it is convenient to group operators together according to the foll
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\WRAP ~|~
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\EXTEND ~|~
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\TRUNC ~|~
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\TRUNC\K{\_sat} ~|~
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\CONVERT ~|~
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\DEMOTE ~|~
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\PROMOTE ~|~

‎document/core/text/instructions.rst‎

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@@ -391,12 +391,20 @@ Numeric Instructions
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\text{i32.trunc\_f32\_u} &\Rightarrow& \I32.\TRUNC\K{\_}\F32\K{\_u} \\ &&|&
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\text{i32.trunc\_f64\_s} &\Rightarrow& \I32.\TRUNC\K{\_}\F64\K{\_s} \\ &&|&
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\text{i32.trunc\_f64\_u} &\Rightarrow& \I32.\TRUNC\K{\_}\F64\K{\_u} \\ &&|&
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\text{i32.trunc\_sat_f32\_s} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F32\K{\_s} \\ &&|&
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\text{i32.trunc\_sat_f32\_u} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F32\K{\_u} \\ &&|&
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\text{i32.trunc\_sat_f64\_s} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F64\K{\_s} \\ &&|&
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\text{i32.trunc\_sat_f64\_u} &\Rightarrow& \I32.\TRUNC\K{\_sat\_}\F64\K{\_u} \\ &&|&
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\text{i64.extend\_i32\_s} &\Rightarrow& \I64.\EXTEND\K{\_}\I32\K{\_s} \\ &&|&
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\text{i64.extend\_i32\_u} &\Rightarrow& \I64.\EXTEND\K{\_}\I32\K{\_u} \\ &&|&
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\text{i64.trunc\_f32\_s} &\Rightarrow& \I64.\TRUNC\K{\_}\F32\K{\_s} \\ &&|&
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\text{i64.trunc\_f32\_u} &\Rightarrow& \I64.\TRUNC\K{\_}\F32\K{\_u} \\ &&|&
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\text{i64.trunc\_f64\_s} &\Rightarrow& \I64.\TRUNC\K{\_}\F64\K{\_s} \\ &&|&
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\text{i64.trunc\_f64\_u} &\Rightarrow& \I64.\TRUNC\K{\_}\F64\K{\_u} \\ &&|&
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\text{i64.trunc\_sat_f32\_s} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F32\K{\_s} \\ &&|&
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\text{i64.trunc\_sat_f32\_u} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F32\K{\_u} \\ &&|&
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\text{i64.trunc\_sat_f64\_s} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F64\K{\_s} \\ &&|&
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\text{i64.trunc\_sat_f64\_u} &\Rightarrow& \I64.\TRUNC\K{\_sat\_}\F64\K{\_u} \\ &&|&
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\text{f32.convert\_i32\_s} &\Rightarrow& \F32.\CONVERT\K{\_}\I32\K{\_s} \\ &&|&
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\text{f32.convert\_i32\_u} &\Rightarrow& \F32.\CONVERT\K{\_}\I32\K{\_u} \\ &&|&
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\text{f32.convert\_i64\_s} &\Rightarrow& \F32.\CONVERT\K{\_}\I64\K{\_s} \\ &&|&

‎document/core/util/macros.def‎

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@@ -948,6 +948,8 @@
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.. |wrap| mathdef:: \xref{exec/numerics}{op-wrap}{\F{wrap}}
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.. |truncu| mathdef:: \xref{exec/numerics}{op-trunc_u}{\F{trunc}^{\K{u}}}
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.. |truncs| mathdef:: \xref{exec/numerics}{op-trunc_s}{\F{trunc}^{\K{s}}}
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.. |truncusat| mathdef:: \xref{exec/numerics}{op-trunc_sat_u}{\F{trunc\_sat\_u}}
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.. |truncssat| mathdef:: \xref{exec/numerics}{op-trunc_sat_s}{\F{trunc\_sat\_s}}
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.. |promote| mathdef:: \xref{exec/numerics}{op-promote}{\F{promote}}
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.. |demote| mathdef:: \xref{exec/numerics}{op-demote}{\F{demote}}
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.. |convertu| mathdef:: \xref{exec/numerics}{op-convert_u}{\F{convert}^{\K{u}}}

‎interpreter/binary/decode.ml‎

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@@ -200,6 +200,19 @@ let memop s =
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let offset = vu32 s in
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Int32.to_int align, offset
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let math_prefix s =
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let pos = pos s in
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match op s with
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| 0x00 -> i32_trunc_sat_f32_s
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| 0x01 -> i32_trunc_sat_f32_u
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| 0x02 -> i32_trunc_sat_f64_s
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| 0x03 -> i32_trunc_sat_f64_u
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| 0x04 -> i64_trunc_sat_f32_s
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| 0x05 -> i64_trunc_sat_f32_u
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| 0x06 -> i64_trunc_sat_f64_s
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| 0x07 -> i64_trunc_sat_f64_u
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| b -> illegal s pos b
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let rec instr s =
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let pos = pos s in
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match op s with
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| 0xbe -> f32_reinterpret_i32
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| 0xbf -> f64_reinterpret_i64
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| 0xfc -> math_prefix s
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| b -> illegal s pos b
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and instr_block s = List.rev (instr_block' s [])

‎interpreter/binary/encode.ml‎

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@@ -336,6 +336,10 @@ let encode m =
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| Convert (I32 I32Op.TruncUF32) -> op 0xa9
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| Convert (I32 I32Op.TruncSF64) -> op 0xaa
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| Convert (I32 I32Op.TruncUF64) -> op 0xab
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| Convert (I32 I32Op.TruncSSatF32) -> op 0xfc; op 0x00
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| Convert (I32 I32Op.TruncUSatF32) -> op 0xfc; op 0x01
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| Convert (I32 I32Op.TruncSSatF64) -> op 0xfc; op 0x02
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| Convert (I32 I32Op.TruncUSatF64) -> op 0xfc; op 0x03
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| Convert (I32 I32Op.ReinterpretFloat) -> op 0xbc
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| Convert (I64 I64Op.ExtendSI32) -> op 0xac
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| Convert (I64 I64Op.TruncUF32) -> op 0xaf
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| Convert (I64 I64Op.TruncSF64) -> op 0xb0
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| Convert (I64 I64Op.TruncUF64) -> op 0xb1
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| Convert (I64 I64Op.TruncSSatF32) -> op 0xfc; op 0x04
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| Convert (I64 I64Op.TruncUSatF32) -> op 0xfc; op 0x05
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| Convert (I64 I64Op.TruncSSatF64) -> op 0xfc; op 0x06
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| Convert (I64 I64Op.TruncUSatF64) -> op 0xfc; op 0x07
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| Convert (I64 I64Op.ReinterpretFloat) -> op 0xbd
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| Convert (F32 F32Op.ConvertSI32) -> op 0xb2

‎interpreter/exec/eval_numeric.ml‎

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@@ -130,6 +130,10 @@ struct
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| TruncUF32 -> I32 (I32_convert.trunc_f32_u (F32Op.of_value 1 v))
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| TruncSF64 -> I32 (I32_convert.trunc_f64_s (F64Op.of_value 1 v))
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| TruncUF64 -> I32 (I32_convert.trunc_f64_u (F64Op.of_value 1 v))
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| TruncSSatF32 -> I32 (I32_convert.trunc_sat_f32_s (F32Op.of_value 1 v))
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| TruncUSatF32 -> I32 (I32_convert.trunc_sat_f32_u (F32Op.of_value 1 v))
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| TruncSSatF64 -> I32 (I32_convert.trunc_sat_f64_s (F64Op.of_value 1 v))
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| TruncUSatF64 -> I32 (I32_convert.trunc_sat_f64_u (F64Op.of_value 1 v))
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| ReinterpretFloat -> I32 (I32_convert.reinterpret_f32 (F32Op.of_value 1 v))
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| ExtendSI32 -> raise (TypeError (1, v, I32Type))
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| ExtendUI32 -> raise (TypeError (1, v, I32Type))
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| TruncUF32 -> I64 (I64_convert.trunc_f32_u (F32Op.of_value 1 v))
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| TruncSF64 -> I64 (I64_convert.trunc_f64_s (F64Op.of_value 1 v))
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| TruncUF64 -> I64 (I64_convert.trunc_f64_u (F64Op.of_value 1 v))
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| TruncSSatF32 -> I64 (I64_convert.trunc_sat_f32_s (F32Op.of_value 1 v))
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| TruncUSatF32 -> I64 (I64_convert.trunc_sat_f32_u (F32Op.of_value 1 v))
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| TruncSSatF64 -> I64 (I64_convert.trunc_sat_f64_s (F64Op.of_value 1 v))
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| TruncUSatF64 -> I64 (I64_convert.trunc_sat_f64_u (F64Op.of_value 1 v))
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| ReinterpretFloat -> I64 (I64_convert.reinterpret_f64 (F64Op.of_value 1 v))
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| WrapI64 -> raise (TypeError (1, v, I64Type))
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end

‎interpreter/exec/i32_convert.ml‎

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@@ -42,4 +42,52 @@ let trunc_f64_u x =
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else
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Int64.(to_int32 (of_float xf))
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let trunc_sat_f32_s x =
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if F32.ne x x then
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0l
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else
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let xf = F32.to_float x in
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if xf < Int32.(to_float min_int) then
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Int32.min_int
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else if xf >= -.Int32.(to_float min_int) then
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Int32.max_int
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else
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Int32.of_float xf
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let trunc_sat_f32_u x =
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if F32.ne x x then
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0l
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else
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let xf = F32.to_float x in
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if xf <= -1.0 then
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0l
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else if xf >= -.Int32.(to_float min_int) *. 2.0 then
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-1l
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else
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Int64.(to_int32 (of_float xf))
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let trunc_sat_f64_s x =
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if F64.ne x x then
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0l
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else
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let xf = F64.to_float x in
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if xf < Int32.(to_float min_int) then
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Int32.min_int
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else if xf >= -.Int32.(to_float min_int) then
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Int32.max_int
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else
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Int32.of_float xf
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let trunc_sat_f64_u x =
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if F64.ne x x then
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0l
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else
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let xf = F64.to_float x in
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if xf <= -1.0 then
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0l
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else if xf >= -.Int32.(to_float min_int) *. 2.0 then
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-1l
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else
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Int64.(to_int32 (of_float xf))
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let reinterpret_f32 = F32.to_bits

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