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[spec/test] Relax relaxed_trunc semantics (#1906)
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‎document/core/exec/numerics.rst

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@@ -2205,20 +2205,20 @@ The implementation-specific behaviour of this operation is determined by the glo
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:math:`\relaxedtrunc^u_{M,N}(z)`
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................................
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The implementation-specific behaviour of this operation is determined by the global parameter :math:`R_{\F{trunc\_u}} \in \{0, 1, 2, 3\}`.
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The implementation-specific behaviour of this operation is determined by the global parameter :math:`R_{\F{trunc\_u}} \in \{0, 1\}`.
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* If :math:`z` is normal or subnormal and :math:`\trunc(z)` is non-negative and less than :math:`2^N`, then return :math:`\truncu_{M,N}(z)`.
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2212-
* Else, return :math:`\relaxed(R_{\F{trunc\_u}})[ \truncsatu_{M,N}(z), 2^N-1, 2^N-2, 2^(N-1) ]`.
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* Else, return :math:`\relaxed(R_{\F{trunc\_u}})[ \truncsatu_{M,N}(z), \mathbf{R} ]`.
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.. math::
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\begin{array}{@{}lcll}
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\relaxedtrunc^u_{M,N}(\pm q) &=& \truncu_{M,N}(\pm q) & (\iff 0 \leq \trunc(\pm q) < 2^N) \\
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\relaxedtrunc^u_{M,N}(z) &=& \relaxed(R_{\F{trunc\_u}})[ \truncsatu_{M,N}(z), 2^{N}-1, 2^{N}-2, 2^{N-1}] & (\otherwise) \\
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\relaxedtrunc^u_{M,N}(z) &=& \relaxed(R_{\F{trunc\_u}})[ \truncsatu_{M,N}(z), \mathbf{R}] & (\otherwise) \\
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\end{array}
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.. note::
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Relaxed unsigned truncation is implementation-dependent for NaNs and out-of-range values.
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Relaxed unsigned truncation is non-deterministic for NaNs and out-of-range values.
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In the :ref:`deterministic profile <profile-deterministic>`,
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it behaves like regular :math:`\truncsatu`.
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@@ -2232,16 +2232,16 @@ The implementation-specific behaviour of this operation is determined by the glo
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* If :math:`z` is normal or subnormal and :math:`\trunc(z)` is greater than or equal to :math:`-2^{N-1}` and less than :math:`2^{N-1}`, then return :math:`\truncs_{M,N}(z)`.
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* Else, return :math:`\relaxed(R_{\F{trunc\_s}})[ \truncsats_{M,N}(z), 2^N-1, 2^N-2, 2^(N-1) ]`.
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* Else, return :math:`\relaxed(R_{\F{trunc\_s}})[ \truncsats_{M,N}(z), \mathbf{R} ]`.
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.. math::
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\begin{array}{@{}lcll}
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\relaxedtrunc^s_{M,N}(\pm q) &=& \truncs_{M,N}(\pm q) & (\iff -2^{N-1} \leq \trunc(\pm q) < 2^{N-1}) \\
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\relaxedtrunc^s_{M,N}(z) &=& \relaxed(R_{\F{trunc\_s}})[ \truncsats_{M,N}(z), \signed^{-1}_N(-2^{N-1})] & (\otherwise) \\
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\relaxedtrunc^s_{M,N}(z) &=& \relaxed(R_{\F{trunc\_s}})[ \truncsats_{M,N}(z), \mathbf{R}] & (\otherwise) \\
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\end{array}
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.. note::
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Relaxed signed truncation is implementation-dependent for NaNs and out-of-range values.
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Relaxed signed truncation is non-deterministic for NaNs and out-of-range values.
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In the :ref:`deterministic profile <profile-deterministic>`,
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it behaves like regular :math:`\truncsats`.
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‎test/core/relaxed-simd/i32x4_relaxed_trunc.wast

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@@ -1,124 +1,8 @@
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;; Tests for i32x4.relaxed_trunc_f32x4_s, i32x4.relaxed_trunc_f32x4_u, i32x4.relaxed_trunc_f64x2_s_zero, and i32x4.relaxed_trunc_f64x2_u_zero.
2-
;; `either` comes from https://github.com/WebAssembly/threads.
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(module
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(func (export "i32x4.relaxed_trunc_f32x4_s") (param v128) (result v128) (i32x4.relaxed_trunc_f32x4_s (local.get 0)))
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(func (export "i32x4.relaxed_trunc_f32x4_u") (param v128) (result v128) (i32x4.relaxed_trunc_f32x4_u (local.get 0)))
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(func (export "i32x4.relaxed_trunc_f64x2_s_zero") (param v128) (result v128) (i32x4.relaxed_trunc_f64x2_s_zero (local.get 0)))
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(func (export "i32x4.relaxed_trunc_f64x2_u_zero") (param v128) (result v128) (i32x4.relaxed_trunc_f64x2_u_zero (local.get 0)))
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(func (export "i32x4.relaxed_trunc_f32x4_s_cmp") (param v128) (result v128)
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(i32x4.eq
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(i32x4.relaxed_trunc_f32x4_s (local.get 0))
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(i32x4.relaxed_trunc_f32x4_s (local.get 0))))
14-
(func (export "i32x4.relaxed_trunc_f32x4_u_cmp") (param v128) (result v128)
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(i32x4.eq
16-
(i32x4.relaxed_trunc_f32x4_u (local.get 0))
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(i32x4.relaxed_trunc_f32x4_u (local.get 0))))
18-
(func (export "i32x4.relaxed_trunc_f64x2_s_zero_cmp") (param v128) (result v128)
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(i32x4.eq
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(i32x4.relaxed_trunc_f64x2_s_zero (local.get 0))
21-
(i32x4.relaxed_trunc_f64x2_s_zero (local.get 0))))
22-
(func (export "i32x4.relaxed_trunc_f64x2_u_zero_cmp") (param v128) (result v128)
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(i32x4.eq
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(i32x4.relaxed_trunc_f64x2_u_zero (local.get 0))
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(i32x4.relaxed_trunc_f64x2_u_zero (local.get 0))))
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)
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;; Test some edge cases around min/max to ensure that the instruction either
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;; saturates correctly or returns INT_MIN.
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;;
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;; Note, though, that INT_MAX itself is not tested. The value for INT_MAX is
32-
;; 2147483647 but that is not representable in a `f32` since it requires 31 bits
33-
;; when a f32 has only 24 bits available. This means that the closest integers
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;; to INT_MAX which can be represented are 2147483520 and 2147483648, meaning
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;; that the INT_MAX test case cannot be tested.
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(assert_return (invoke "i32x4.relaxed_trunc_f32x4_s"
37-
;; INT32_MIN <INT32_MIN >INT32_MAX
38-
(v128.const f32x4 -2147483648.0 -2147483904.0 2.0 2147483904.0))
39-
;; out of range -> saturate or INT32_MIN
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(either (v128.const i32x4 -2147483648 -2147483648 2 2147483647)
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(v128.const i32x4 -2147483648 -2147483648 2 -2147483648)))
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43-
(assert_return (invoke "i32x4.relaxed_trunc_f32x4_s"
44-
(v128.const f32x4 nan -nan nan:0x444444 -nan:0x444444))
45-
;; nans -> 0 or INT32_MIN
46-
(either (v128.const i32x4 0 0 0 0)
47-
(v128.const i32x4 0x80000000 0x80000000 0x80000000 0x80000000)))
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49-
(assert_return (invoke "i32x4.relaxed_trunc_f32x4_u"
50-
;; UINT32_MIN UINT32_MIN-1 <UINT32_MAX UINT32_MAX+1
51-
(v128.const f32x4 0 -1.0 4294967040.0 4294967296.0))
52-
;; out of range -> saturate or UINT32_MAX
53-
(either (v128.const i32x4 0 0 4294967040 0xffffffff)
54-
(v128.const i32x4 0 0xffffffff 4294967040 0xffffffff)))
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56-
(assert_return (invoke "i32x4.relaxed_trunc_f32x4_u"
57-
(v128.const f32x4 nan -nan nan:0x444444 -nan:0x444444))
58-
;; nans -> 0 or UINT32_MAX
59-
(either (v128.const i32x4 0 0 0 0)
60-
(v128.const i32x4 0xffffffff 0xffffffff 0xffffffff 0xffffffff)))
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62-
(assert_return (invoke "i32x4.relaxed_trunc_f64x2_s_zero"
63-
(v128.const f64x2 -2147483904.0 2147483904.0))
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;; out of range -> saturate or INT32_MIN
65-
(either (v128.const i32x4 -2147483648 2147483647 0 0)
66-
(v128.const i32x4 -2147483648 -2147483648 0 0)))
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68-
(assert_return (invoke "i32x4.relaxed_trunc_f64x2_s_zero"
69-
(v128.const f64x2 nan -nan))
70-
(either (v128.const i32x4 0 0 0 0)
71-
(v128.const i32x4 0x80000000 0x80000000 0 0)))
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73-
(assert_return (invoke "i32x4.relaxed_trunc_f64x2_u_zero"
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(v128.const f64x2 -1.0 4294967296.0))
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;; out of range -> saturate or UINT32_MAX
76-
(either (v128.const i32x4 0 0xffffffff 0 0)
77-
(v128.const i32x4 0xffffffff 0xffffffff 0 0)))
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79-
(assert_return (invoke "i32x4.relaxed_trunc_f64x2_u_zero"
80-
(v128.const f64x2 nan -nan))
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(either (v128.const i32x4 0 0 0 0)
82-
(v128.const i32x4 0 0 0xffffffff 0xffffffff)))
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84-
;; Check that multiple calls to the relaxed instruction with same inputs returns same results.
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86-
(assert_return (invoke "i32x4.relaxed_trunc_f32x4_s_cmp"
87-
;; INT32_MIN <INT32_MIN INT32_MAX >INT32_MAX
88-
(v128.const f32x4 -2147483648.0 -2147483904.0 2147483647.0 2147483904.0))
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;; out of range -> saturate or INT32_MIN
90-
(v128.const i32x4 -1 -1 -1 -1))
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92-
(assert_return (invoke "i32x4.relaxed_trunc_f32x4_s_cmp"
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(v128.const f32x4 nan -nan nan:0x444444 -nan:0x444444))
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;; nans -> 0 or INT32_MIN
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(v128.const i32x4 -1 -1 -1 -1))
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(assert_return (invoke "i32x4.relaxed_trunc_f32x4_u_cmp"
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;; UINT32_MIN UINT32_MIN-1 <UINT32_MAX UINT32_MAX+1
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(v128.const f32x4 0 -1.0 4294967040.0 4294967296.0))
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;; out of range -> saturate or UINT32_MAX
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(v128.const i32x4 -1 -1 -1 -1))
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103-
(assert_return (invoke "i32x4.relaxed_trunc_f32x4_u_cmp"
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(v128.const f32x4 nan -nan nan:0x444444 -nan:0x444444))
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;; nans -> 0 or UINT32_MAX
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(v128.const i32x4 -1 -1 -1 -1))
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108-
(assert_return (invoke "i32x4.relaxed_trunc_f64x2_s_zero_cmp"
109-
(v128.const f64x2 -2147483904.0 2147483904.0))
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;; out of range -> saturate or INT32_MIN
111-
(v128.const i32x4 -1 -1 -1 -1))
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113-
(assert_return (invoke "i32x4.relaxed_trunc_f64x2_s_zero_cmp"
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(v128.const f64x2 nan -nan))
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(v128.const i32x4 -1 -1 -1 -1))
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(assert_return (invoke "i32x4.relaxed_trunc_f64x2_u_zero_cmp"
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(v128.const f64x2 -1.0 4294967296.0))
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;; out of range -> saturate or UINT32_MAX
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(v128.const i32x4 -1 -1 -1 -1))
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(assert_return (invoke "i32x4.relaxed_trunc_f64x2_u_zero_cmp"
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(v128.const f64x2 nan -nan))
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(v128.const i32x4 -1 -1 -1 -1))

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