forked from OSchip/llvm-project
[PPC] Refine checks for emiting TOC restore nop and tail-call eligibility.
For the medium and large code models we only need to check if a call crosses dso-boundaries when considering tail-call elgibility. Differential Revision: https://reviews.llvm.org/D34245 llvm-svn: 311353
This commit is contained in:
Sean Fertile
parent
e963c89d11
commit
00393cce3a
|
|
@ -4255,13 +4255,25 @@ static int CalculateTailCallSPDiff(SelectionDAG& DAG, bool isTailCall,
|
|||
static bool isFunctionGlobalAddress(SDValue Callee);
|
||||
|
||||
static bool
|
||||
resideInSameSection(const Function *Caller, SDValue Callee,
|
||||
callsShareTOCBase(const Function *Caller, SDValue Callee,
|
||||
const TargetMachine &TM) {
|
||||
// If !G, Callee can be an external symbol.
|
||||
GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee);
|
||||
if (!G)
|
||||
return false;
|
||||
|
||||
// The medium and large code models are expected to provide a sufficiently
|
||||
// large TOC to provide all data addressing needs of a module with a
|
||||
// single TOC. Since each module will be addressed with a single TOC then we
|
||||
// only need to check that caller and callee don't cross dso boundaries.
|
||||
if (CodeModel::Medium == TM.getCodeModel() ||
|
||||
CodeModel::Large == TM.getCodeModel())
|
||||
return TM.shouldAssumeDSOLocal(*Caller->getParent(), G->getGlobal());
|
||||
|
||||
// Otherwise we need to ensure callee and caller are in the same section,
|
||||
// since the linker may allocate multiple TOCs, and we don't know which
|
||||
// sections will belong to the same TOC base.
|
||||
|
||||
const GlobalValue *GV = G->getGlobal();
|
||||
if (!GV->isStrongDefinitionForLinker())
|
||||
return false;
|
||||
|
|
@ -4410,11 +4422,10 @@ PPCTargetLowering::IsEligibleForTailCallOptimization_64SVR4(
|
|||
!isa<ExternalSymbolSDNode>(Callee))
|
||||
return false;
|
||||
|
||||
// Check if Callee resides in the same section, because for now, PPC64 SVR4
|
||||
// ABI (ELFv1/ELFv2) doesn't allow tail calls to a symbol resides in another
|
||||
// section.
|
||||
// If the caller and callee potentially have different TOC bases then we
|
||||
// cannot tail call since we need to restore the TOC pointer after the call.
|
||||
// ref: https://bugzilla.mozilla.org/show_bug.cgi?id=973977
|
||||
if (!resideInSameSection(MF.getFunction(), Callee, getTargetMachine()))
|
||||
if (!callsShareTOCBase(MF.getFunction(), Callee, getTargetMachine()))
|
||||
return false;
|
||||
|
||||
// TCO allows altering callee ABI, so we don't have to check further.
|
||||
|
|
@ -4996,7 +5007,7 @@ SDValue PPCTargetLowering::FinishCall(
|
|||
// any other variadic arguments).
|
||||
Ops.insert(std::next(Ops.begin()), AddTOC);
|
||||
} else if (CallOpc == PPCISD::CALL &&
|
||||
!resideInSameSection(MF.getFunction(), Callee, DAG.getTarget())) {
|
||||
!callsShareTOCBase(MF.getFunction(), Callee, DAG.getTarget())) {
|
||||
// Otherwise insert NOP for non-local calls.
|
||||
CallOpc = PPCISD::CALL_NOP;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -5,6 +5,8 @@
|
|||
; RUN: llc < %s -function-sections -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu | FileCheck %s -check-prefix=CHECK-FS
|
||||
; RUN: llc < %s -relocation-model=pic -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu | FileCheck %s
|
||||
; RUN: llc < %s -function-sections -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu | FileCheck %s -check-prefix=CHECK-FS
|
||||
; RUN: llc < %s -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu \
|
||||
; RUN: -code-model=small -mcpu=pwr8 | FileCheck %s -check-prefix=SCM
|
||||
|
||||
%class.T = type { [2 x i8] }
|
||||
|
||||
|
|
@ -74,7 +76,11 @@ define void @wo_hcaller(%class.T* %this, i8* %c) {
|
|||
|
||||
; CHECK-LABEL: wo_hcaller:
|
||||
; CHECK: bl wo_hcallee
|
||||
; CHECK-NEXT: nop
|
||||
; CHECK-NOT: nop
|
||||
|
||||
; SCM-LABEL: wo_hcaller:
|
||||
; SCM: bl wo_hcallee
|
||||
; SCM-NEXT: nop
|
||||
}
|
||||
|
||||
define weak_odr protected void @wo_pcallee(%class.T* %this, i8* %c) { ret void }
|
||||
|
|
@ -84,7 +90,11 @@ define void @wo_pcaller(%class.T* %this, i8* %c) {
|
|||
|
||||
; CHECK-LABEL: wo_pcaller:
|
||||
; CHECK: bl wo_pcallee
|
||||
; CHECK-NEXT: nop
|
||||
; CHECK-NOT: nop
|
||||
|
||||
; SCM-LABEL: wo_pcaller:
|
||||
; SCM: bl wo_pcallee
|
||||
; SCM-NEXT: nop
|
||||
}
|
||||
|
||||
define weak_odr void @wo_callee(%class.T* %this, i8* %c) { ret void }
|
||||
|
|
@ -104,7 +114,11 @@ define void @w_pcaller(i8* %ptr) {
|
|||
|
||||
; CHECK-LABEL: w_pcaller:
|
||||
; CHECK: bl w_pcallee
|
||||
; CHECK-NEXT: nop
|
||||
; CHECK-NOT: nop
|
||||
|
||||
; SCM-LABEL: w_pcaller:
|
||||
; SCM: bl w_pcallee
|
||||
; SCM-NEXT: nop
|
||||
}
|
||||
|
||||
define weak hidden void @w_hcallee(i8* %ptr) { ret void }
|
||||
|
|
@ -114,7 +128,11 @@ define void @w_hcaller(i8* %ptr) {
|
|||
|
||||
; CHECK-LABEL: w_hcaller:
|
||||
; CHECK: bl w_hcallee
|
||||
; CHECK-NEXT: nop
|
||||
; CHECK-NOT: nop
|
||||
|
||||
; SCM-LABEL: w_hcaller:
|
||||
; SCM: bl w_hcallee
|
||||
; SCM-NEXT: nop
|
||||
}
|
||||
|
||||
define weak void @w_callee(i8* %ptr) { ret void }
|
||||
|
|
|
|||
|
|
@ -1,4 +1,6 @@
|
|||
; RUN: llc -relocation-model=static -verify-machineinstrs < %s -mcpu=pwr7 | FileCheck %s
|
||||
; RUN: llc -relocation-model=static -verify-machineinstrs < %s -code-model=small -mcpu=pwr7 | FileCheck %s -check-prefix=SCM
|
||||
|
||||
target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v128:128:128-n32:64"
|
||||
target triple = "powerpc64-unknown-linux-gnu"
|
||||
|
||||
|
|
@ -21,13 +23,22 @@ define void @test_direct() nounwind readnone {
|
|||
ret void
|
||||
}
|
||||
|
||||
; Calls to weak function requires a TOC restore 'nop' because they
|
||||
; may be overridden in a different module.
|
||||
; Calls to weak function requires a TOC restore 'nop' with the small codemodel
|
||||
; because the definition that gets choosen at link time may come from a
|
||||
; different section even though we have seen a weak definition in the same
|
||||
; section at compile time.
|
||||
; With large and medium codemodels no TOC restore is needed, since we know
|
||||
; whichever definition is choosen it resides within the same DSO boundaries and
|
||||
; therefore shares the same TOC.
|
||||
define void @test_weak() nounwind readnone {
|
||||
; CHECK-LABEL: test_weak:
|
||||
tail call void @foo_weak() nounwind
|
||||
; CHECK: bl foo
|
||||
; CHECK-NEXT: nop
|
||||
; CHECK-LABEL: test_weak:
|
||||
; CHECK: b foo_weak
|
||||
; CHECK-NOT: nop
|
||||
|
||||
; SCM-LABEL: test_weak:
|
||||
; SCM: bl foo_weak
|
||||
; SCM-NEXT: nop
|
||||
ret void
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -1,6 +1,7 @@
|
|||
; RUN: llc < %s -relocation-model=static -O1 -disable-ppc-sco=false -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu | FileCheck %s -check-prefix=CHECK-SCO
|
||||
; RUN: llc < %s -relocation-model=static -O1 -disable-ppc-sco=false -verify-machineinstrs -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr8 | FileCheck %s -check-prefix=CHECK-SCO-HASQPX
|
||||
; RUN: llc < %s -relocation-model=static -O1 -disable-ppc-sco=false -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 | FileCheck %s -check-prefix=CHECK-SCO-HASQPX
|
||||
; RUN: llc < %s -relocation-model=static -O1 -disable-ppc-sco=false -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 -code-model=small | FileCheck %s -check-prefix=SCM
|
||||
|
||||
; No combination of "powerpc64le-unknown-linux-gnu" + "CHECK-SCO", because
|
||||
; only Power8 (and later) fully support LE.
|
||||
|
|
@ -142,7 +143,10 @@ define void @wo_hcaller(%class.T* %this, i8* %c) {
|
|||
ret void
|
||||
|
||||
; CHECK-SCO-LABEL: wo_hcaller:
|
||||
; CHECK-SCO: bl wo_hcallee
|
||||
; CHECK-SCO: b wo_hcallee
|
||||
|
||||
; SCM-LABEL: wo_hcaller:
|
||||
; SCM: bl wo_hcallee
|
||||
}
|
||||
|
||||
define weak_odr protected void @wo_pcallee(%class.T* %this, i8* %c) { ret void }
|
||||
|
|
@ -151,7 +155,10 @@ define void @wo_pcaller(%class.T* %this, i8* %c) {
|
|||
ret void
|
||||
|
||||
; CHECK-SCO-LABEL: wo_pcaller:
|
||||
; CHECK-SCO: bl wo_pcallee
|
||||
; CHECK-SCO: b wo_pcallee
|
||||
|
||||
; SCM-LABEL: wo_pcaller:
|
||||
; SCM: bl wo_pcallee
|
||||
}
|
||||
|
||||
define weak_odr void @wo_callee(%class.T* %this, i8* %c) { ret void }
|
||||
|
|
@ -160,7 +167,10 @@ define void @wo_caller(%class.T* %this, i8* %c) {
|
|||
ret void
|
||||
|
||||
; CHECK-SCO-LABEL: wo_caller:
|
||||
; CHECK-SCO: bl wo_callee
|
||||
; CHECK-SCO: b wo_callee
|
||||
|
||||
; SCM-LABEL: wo_caller:
|
||||
; SCM: bl wo_callee
|
||||
}
|
||||
|
||||
define weak protected void @w_pcallee(i8* %ptr) { ret void }
|
||||
|
|
@ -169,7 +179,10 @@ define void @w_pcaller(i8* %ptr) {
|
|||
ret void
|
||||
|
||||
; CHECK-SCO-LABEL: w_pcaller:
|
||||
; CHECK-SCO: bl w_pcallee
|
||||
; CHECK-SCO: b w_pcallee
|
||||
|
||||
; SCM-LABEL: w_pcaller:
|
||||
; SCM: bl w_pcallee
|
||||
}
|
||||
|
||||
define weak hidden void @w_hcallee(i8* %ptr) { ret void }
|
||||
|
|
@ -178,7 +191,10 @@ define void @w_hcaller(i8* %ptr) {
|
|||
ret void
|
||||
|
||||
; CHECK-SCO-LABEL: w_hcaller:
|
||||
; CHECK-SCO: bl w_hcallee
|
||||
; CHECK-SCO: b w_hcallee
|
||||
|
||||
; SCM-LABEL: w_hcaller:
|
||||
; SCM: bl w_hcallee
|
||||
}
|
||||
|
||||
define weak void @w_callee(i8* %ptr) { ret void }
|
||||
|
|
@ -187,7 +203,10 @@ define void @w_caller(i8* %ptr) {
|
|||
ret void
|
||||
|
||||
; CHECK-SCO-LABEL: w_caller:
|
||||
; CHECK-SCO: bl w_callee
|
||||
; CHECK-SCO: b w_callee
|
||||
|
||||
; SCM-LABEL: w_caller:
|
||||
; SCM: bl w_callee
|
||||
}
|
||||
|
||||
%struct.byvalTest = type { [8 x i8] }
|
||||
|
|
|
|||
Loading…
Reference in New Issue