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10a200e560
When casting an ideal to complex{64,128}, for example during the
evaluation of
var a = complex64(0) / 1e-50
we want the compiler to report a division-by-zero error if a divisor
would be zero after the cast.
We already do this for floats; for example
var b = float32(0) / 1e-50
generates a 'division by zero' error at compile time (because
float32(1e-50) is zero, and the cast is done before performing the
division).
There's no such check in the path for complex{64,128} expressions, and
no cast is performed before the division in the evaluation of
var a = complex64(0) / 1e-50
which compiles just fine.
This patch changes the convlit1 function so that complex ideals
components (real and imag) are correctly truncated to float{32,64}
when doing an ideal -> complex{64, 128} cast.
Fixes #11674
Change-Id: Ic5f8ee3c8cfe4c3bb0621481792c96511723d151
Reviewed-on: https://go-review.googlesource.com/37891
Run-TryBot: Alberto Donizetti <alb.donizetti@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
41 lines
1.2 KiB
Go
41 lines
1.2 KiB
Go
// errorcheck
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// Copyright 2017 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Issue 11674: cmd/compile: does not diagnose constant division by
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// zero
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package p
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const x complex64 = 0
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const y complex128 = 0
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var _ = x / 1e-20
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var _ = x / 1e-50 // ERROR "complex division by zero"
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var _ = x / 1e-1000 // ERROR "complex division by zero"
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var _ = x / 1e-20i
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var _ = x / 1e-50i // ERROR "complex division by zero"
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var _ = x / 1e-1000i // ERROR "complex division by zero"
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var _ = x / 1e-45 // smallest positive float32
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var _ = x / (1e-20 + 1e-20i)
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var _ = x / (1e-50 + 1e-20i)
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var _ = x / (1e-20 + 1e-50i)
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var _ = x / (1e-50 + 1e-50i) // ERROR "complex division by zero"
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var _ = x / (1e-1000 + 1e-1000i) // ERROR "complex division by zero"
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var _ = y / 1e-50
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var _ = y / 1e-1000 // ERROR "complex division by zero"
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var _ = y / 1e-50i
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var _ = y / 1e-1000i // ERROR "complex division by zero"
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var _ = y / 5e-324 // smallest positive float64
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var _ = y / (1e-50 + 1e-50)
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var _ = y / (1e-1000 + 1e-50i)
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var _ = y / (1e-50 + 1e-1000i)
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var _ = y / (1e-1000 + 1e-1000i) // ERROR "complex division by zero"
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