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cmd/internal/obj, cmd/link, runtime: increase stack limit to accommodate larger frames on ppc64x

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Larger stack frames mean nosplit functions use more stack and so the limit
needs to increase.

The change to test/nosplit.go is a bit ugly but I can't really think of a
way to make it nicer.

Change-Id: I2616b58015f0b62abbd62951575fcd0d2d8643c2
Reviewed-on: https://go-review.googlesource.com/16504
Reviewed-by: Russ Cox <rsc@golang.org>
This commit is contained in:
Michael Hudson-Doyle 2015-10-30 12:47:24 +13:00
parent c3ba74931f
commit c1b6e392f5
3 changed files with 41 additions and 27 deletions
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2
src/cmd/internal/obj/stack.go
View file

@ -41,7 +41,7 @@ const (
STACKSYSTEM = 0
StackSystem = STACKSYSTEM
StackBig = 4096
StackGuard = 640*stackGuardMultiplier + StackSystem
StackGuard = 720*stackGuardMultiplier + StackSystem
StackSmall = 128
StackLimit = StackGuard - StackSystem - StackSmall
)

2
src/runtime/stack.go
View file

@ -90,7 +90,7 @@ const (
// The stack guard is a pointer this many bytes above the
// bottom of the stack.
_StackGuard = 640*sys.StackGuardMultiplier + _StackSystem
_StackGuard = 720*sys.StackGuardMultiplier + _StackSystem
// After a stack split check the SP is allowed to be this
// many bytes below the stack guard. This saves an instruction

64
test/nosplit.go
View file

@ -115,10 +115,15 @@ main 132
main 136
# A nosplit leaf can use the whole 128-CallSize bytes available on entry.
main 112 nosplit
main 116 nosplit
main 120 nosplit
main 124 nosplit
# (CallSize is 32 on ppc64)
main 96 nosplit
main 100 nosplit; REJECT ppc64 ppc64le
main 104 nosplit; REJECT ppc64 ppc64le
main 108 nosplit; REJECT ppc64 ppc64le
main 112 nosplit; REJECT ppc64 ppc64le
main 116 nosplit; REJECT ppc64 ppc64le
main 120 nosplit; REJECT ppc64 ppc64le
main 124 nosplit; REJECT ppc64 ppc64le
main 128 nosplit; REJECT
main 132 nosplit; REJECT
main 136 nosplit; REJECT
@ -126,11 +131,16 @@ main 136 nosplit; REJECT
# Calling a nosplit function from a nosplit function requires
# having room for the saved caller PC and the called frame.
# Because ARM doesn't save LR in the leaf, it gets an extra 4 bytes.
# Because ppc64 doesn't save LR in the leaf, it gets an extra 8 bytes.
main 112 nosplit call f; f 0 nosplit
main 116 nosplit call f; f 0 nosplit
main 120 nosplit call f; f 0 nosplit; REJECT amd64
main 124 nosplit call f; f 0 nosplit; REJECT amd64 386
# Because arm64 doesn't save LR in the leaf, it gets an extra 8 bytes.
# ppc64 doesn't save LR in the leaf, but CallSize is 32, so it gets 24 fewer bytes than amd64.
main 96 nosplit call f; f 0 nosplit
main 100 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le
main 104 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le
main 108 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le
main 112 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le
main 116 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le
main 120 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le amd64
main 124 nosplit call f; f 0 nosplit; REJECT ppc64 ppc64le amd64 386
main 128 nosplit call f; f 0 nosplit; REJECT
main 132 nosplit call f; f 0 nosplit; REJECT
main 136 nosplit call f; f 0 nosplit; REJECT
@ -138,24 +148,28 @@ main 136 nosplit call f; f 0 nosplit; REJECT
# Calling a splitting function from a nosplit function requires
# having room for the saved caller PC of the call but also the
# saved caller PC for the call to morestack.
# Again the ARM and ppc64 work in less space.
main 104 nosplit call f; f 0 call f
main 108 nosplit call f; f 0 call f
main 112 nosplit call f; f 0 call f; REJECT amd64
main 116 nosplit call f; f 0 call f; REJECT amd64
main 120 nosplit call f; f 0 call f; REJECT amd64 386
main 124 nosplit call f; f 0 call f; REJECT amd64 386
# RISC architectures differ in the same way as before.
main 96 nosplit call f; f 0 call f
main 100 nosplit call f; f 0 call f; REJECT ppc64 ppc64le
main 104 nosplit call f; f 0 call f; REJECT ppc64 ppc64le
main 108 nosplit call f; f 0 call f; REJECT ppc64 ppc64le
main 112 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64
main 116 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64
main 120 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64 386
main 124 nosplit call f; f 0 call f; REJECT ppc64 ppc64le amd64 386
main 128 nosplit call f; f 0 call f; REJECT
main 132 nosplit call f; f 0 call f; REJECT
main 136 nosplit call f; f 0 call f; REJECT
# Indirect calls are assumed to be splitting functions.
main 104 nosplit callind
main 108 nosplit callind
main 112 nosplit callind; REJECT amd64
main 116 nosplit callind; REJECT amd64
main 120 nosplit callind; REJECT amd64 386
main 124 nosplit callind; REJECT amd64 386
main 96 nosplit callind
main 100 nosplit callind; REJECT ppc64 ppc64le
main 104 nosplit callind; REJECT ppc64 ppc64le
main 108 nosplit callind; REJECT ppc64 ppc64le
main 112 nosplit callind; REJECT ppc64 ppc64le amd64
main 116 nosplit callind; REJECT ppc64 ppc64le amd64
main 120 nosplit callind; REJECT ppc64 ppc64le amd64 386
main 124 nosplit callind; REJECT ppc64 ppc64le amd64 386
main 128 nosplit callind; REJECT
main 132 nosplit callind; REJECT
main 136 nosplit callind; REJECT
@ -284,16 +298,16 @@ TestCases:
name := m[1]
size, _ := strconv.Atoi(m[2])
// The limit was originally 128 but is now 512.
// The limit was originally 128 but is now 592.
// Instead of rewriting the test cases above, adjust
// the first stack frame to use up the extra bytes.
if i == 0 {
size += 512 - 128
size += 592 - 128
// Noopt builds have a larger stackguard.
// See ../cmd/dist/buildruntime.go:stackGuardMultiplier
for _, s := range strings.Split(os.Getenv("GO_GCFLAGS"), " ") {
if s == "-N" {
size += 640
size += 720
}
}
}