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389e942745
Instead of allocating a new temporary each time one
is needed, keep a list of temporaries which are free
(have already been VARKILLed on every path) and use
one of them.
Should save a lot of stack space. In a function like this:
func main() {
fmt.Printf("%d %d\n", 2, 3)
fmt.Printf("%d %d\n", 4, 5)
fmt.Printf("%d %d\n", 6, 7)
}
The three [2]interface{} arrays used to hold the ... args
all use the same autotmp, instead of 3 different autotmps
as happened previous to this CL.
Change-Id: I2d728e226f81e05ae68ca8247af62014a1b032d3
Reviewed-on: https://go-review.googlesource.com/c/140301
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
44 lines
1.5 KiB
Go
44 lines
1.5 KiB
Go
// errorcheck -0 -m -live
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// Copyright 2016 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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// Test escape analysis and liveness inferred for uintptrescapes functions.
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package p
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import (
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"unsafe"
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)
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//go:uintptrescapes
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//go:noinline
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func F1(a uintptr) {} // ERROR "escaping uintptr"
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//go:uintptrescapes
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//go:noinline
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func F2(a ...uintptr) {} // ERROR "escaping ...uintptr" "a does not escape"
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//go:uintptrescapes
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//go:noinline
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func F3(uintptr) {} // ERROR "escaping uintptr"
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//go:uintptrescapes
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//go:noinline
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func F4(...uintptr) {} // ERROR "escaping ...uintptr"
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func G() {
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var t int // ERROR "moved to heap"
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F1(uintptr(unsafe.Pointer(&t))) // ERROR "live at call to F1: .?autotmp" "&t escapes to heap" "stack object .autotmp_[0-9]+ unsafe.Pointer$"
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var t2 int // ERROR "moved to heap"
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F3(uintptr(unsafe.Pointer(&t2))) // ERROR "live at call to F3: .?autotmp" "&t2 escapes to heap"
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}
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func H() {
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var v int // ERROR "moved to heap"
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F2(0, 1, uintptr(unsafe.Pointer(&v)), 2) // ERROR "live at call to newobject: .?autotmp" "live at call to F2: .?autotmp" "escapes to heap" "stack object .autotmp_[0-9]+ unsafe.Pointer$"
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var v2 int // ERROR "moved to heap"
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F4(0, 1, uintptr(unsafe.Pointer(&v2)), 2) // ERROR "live at call to newobject: .?autotmp" "live at call to F4: .?autotmp" "escapes to heap"
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}
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