StrixOS/build_soong
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add support for thin LTO

Browse Source 
ThinLTO achieves comparable performance to full LTO while taking much
less time for compilation.

Test: Build hwui with "thin" and "full" LTO
Change-Id: If3400b82af0d5e0226410c8b740999cdad746a59
This commit is contained in:
Yi Kong
2017-08-29 11:10:09 +08:00
parent 8edbb3acc9
commit 244bf079f9
1 changed files with 26 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
cc/lto.go
View File

@@ -41,7 +41,10 @@ import (
type LTOProperties struct { type LTOProperties struct {
// Lto must violate capitialization style for acronyms so that it can be // Lto must violate capitialization style for acronyms so that it can be
// referred to in blueprint files as "lto" // referred to in blueprint files as "lto"
Lto *bool `android:"arch_variant"` Lto struct {
Full *bool `android:"arch_variant"`
Thin *bool `android:"arch_variant"`
} `android:"arch_variant"`
LTODep bool `blueprint:"mutated"` LTODep bool `blueprint:"mutated"`
} }
@@ -61,9 +64,16 @@ func (lto *lto) deps(ctx BaseModuleContext, deps Deps) Deps {
} }
func (lto *lto) flags(ctx BaseModuleContext, flags Flags) Flags { func (lto *lto) flags(ctx BaseModuleContext, flags Flags) Flags {
if Bool(lto.Properties.Lto) { if lto.LTO() {
flags.CFlags = append(flags.CFlags, "-flto") var ltoFlag string
flags.LdFlags = append(flags.LdFlags, "-flto") if Bool(lto.Properties.Lto.Thin) {
ltoFlag = "-flto=thin"
} else {
ltoFlag = "-flto"
}
flags.CFlags = append(flags.CFlags, ltoFlag)
flags.LdFlags = append(flags.LdFlags, ltoFlag)
if ctx.Device() { if ctx.Device() {
// Work around bug in Clang that doesn't pass correct emulated // Work around bug in Clang that doesn't pass correct emulated
// TLS option to target // TLS option to target
@@ -80,12 +90,20 @@ func (lto *lto) LTO() bool {
return false return false
} }
return Bool(lto.Properties.Lto) full := Bool(lto.Properties.Lto.Full)
thin := Bool(lto.Properties.Lto.Thin)
return full || thin
} }
// Propagate lto requirements down from binaries // Propagate lto requirements down from binaries
func ltoDepsMutator(mctx android.TopDownMutatorContext) { func ltoDepsMutator(mctx android.TopDownMutatorContext) {
if c, ok := mctx.Module().(*Module); ok && c.lto.LTO() { if c, ok := mctx.Module().(*Module); ok && c.lto.LTO() {
full := Bool(c.lto.Properties.Lto.Full)
thin := Bool(c.lto.Properties.Lto.Thin)
if full && thin {
mctx.PropertyErrorf("LTO", "FullLTO and ThinLTO are mutually exclusive")
}
mctx.VisitDepsDepthFirst(func(m blueprint.Module) { mctx.VisitDepsDepthFirst(func(m blueprint.Module) {
tag := mctx.OtherModuleDependencyTag(m) tag := mctx.OtherModuleDependencyTag(m)
switch tag { switch tag {
@@ -105,8 +123,8 @@ func ltoMutator(mctx android.BottomUpMutatorContext) {
mctx.SetDependencyVariation("lto") mctx.SetDependencyVariation("lto")
} else if c.lto.Properties.LTODep { } else if c.lto.Properties.LTODep {
modules := mctx.CreateVariations("", "lto") modules := mctx.CreateVariations("", "lto")
modules[0].(*Module).lto.Properties.Lto = boolPtr(false) modules[0].(*Module).lto.Properties.Lto.Full = boolPtr(false)
modules[1].(*Module).lto.Properties.Lto = boolPtr(true) modules[0].(*Module).lto.Properties.Lto.Thin = boolPtr(false)
modules[0].(*Module).lto.Properties.LTODep = false modules[0].(*Module).lto.Properties.LTODep = false
modules[1].(*Module).lto.Properties.LTODep = false modules[1].(*Module).lto.Properties.LTODep = false
modules[1].(*Module).Properties.PreventInstall = true modules[1].(*Module).Properties.PreventInstall = true