From 0e3246a86f553aa6fae35d3bfb91de81dd66a18b Mon Sep 17 00:00:00 2001
From: Akira Hatanaka <ahatanaka@apple.com>
Date: Tue, 9 Jun 2015 19:07:19 +0000
Subject: [PATCH] Remove DisableTailCalls from TargetOptions and the code in
resetTargetOptions that was resetting it.
Remove the uses of DisableTailCalls in subclasses of TargetLowering and use
the value of function attribute "disable-tail-calls" instead. Also,
unconditionally add pass TailCallElim to the pipeline and check the function
attribute at the start of runOnFunction to disable the pass on a per-function
basis.
This is part of the work to remove TargetMachine::resetTargetOptions, and since
DisableTailCalls was the last non-fast-math option that was being reset in that
function, we should be able to remove the function entirely after the work to
propagate IR-level fast-math flags to DAG nodes is completed.
Out-of-tree users should remove the uses of DisableTailCalls and make changes
to attach attribute "disable-tail-calls"="true" or "false" to the functions in
the IR.
rdar://problem/13752163
Differential Revision: http://reviews.llvm.org/D10099
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@239427 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/llvm/CodeGen/CommandFlags.h | 7 +++-
include/llvm/Target/TargetOptions.h | 7 +---
lib/Target/ARM/ARMISelLowering.cpp | 7 +++-
lib/Target/Hexagon/HexagonISelLowering.cpp | 7 +++-
lib/Target/TargetMachine.cpp | 1 -
lib/Target/X86/X86ISelLowering.cpp | 7 +++-
lib/Transforms/IPO/PassManagerBuilder.cpp | 4 +-
.../Scalar/TailRecursionElimination.cpp | 3 ++
test/CodeGen/ARM/disable-tail-calls.ll | 40 +++++++++++++++++++
test/CodeGen/X86/disable-tail-calls.ll | 40 +++++++++++++++++++
10 files changed, 106 insertions(+), 17 deletions(-)
create mode 100644 test/CodeGen/ARM/disable-tail-calls.ll
create mode 100644 test/CodeGen/X86/disable-tail-calls.ll
diff --git a/include/llvm/CodeGen/CommandFlags.h b/include/llvm/CodeGen/CommandFlags.h
index b824df3013d..c5183dc42b1 100644
--- a/include/llvm/CodeGen/CommandFlags.h
+++ b/include/llvm/CodeGen/CommandFlags.h
@@ -16,6 +16,7 @@
#ifndef LLVM_CODEGEN_COMMANDFLAGS_H
#define LLVM_CODEGEN_COMMANDFLAGS_H
+#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/Module.h"
#include "llvm/MC/MCTargetOptionsCommandFlags.h"
#include "llvm//MC/SubtargetFeature.h"
@@ -247,7 +248,6 @@ static inline TargetOptions InitTargetOptionsFromCodeGenFlags() {
Options.FloatABIType = FloatABIForCalls;
Options.NoZerosInBSS = DontPlaceZerosInBSS;
Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt;
- Options.DisableTailCalls = DisableTailCalls;
Options.StackAlignmentOverride = OverrideStackAlignment;
Options.TrapFuncName = TrapFuncName;
Options.PositionIndependentExecutable = EnablePIE;
@@ -315,6 +315,11 @@ static inline void setFunctionAttributes(StringRef CPU, StringRef Features,
"no-frame-pointer-elim",
DisableFPElim ? "true" : "false");
+ if (DisableTailCalls.getNumOccurrences() > 0)
+ NewAttrs = NewAttrs.addAttribute(Ctx, AttributeSet::FunctionIndex,
+ "disable-tail-calls",
+ toStringRef(DisableTailCalls));
+
// Let NewAttrs override Attrs.
NewAttrs = Attrs.addAttributes(Ctx, AttributeSet::FunctionIndex, NewAttrs);
F.setAttributes(NewAttrs);
diff --git a/include/llvm/Target/TargetOptions.h b/include/llvm/Target/TargetOptions.h
index 8f8b78d9b0b..a4e0954129d 100644
--- a/include/llvm/Target/TargetOptions.h
+++ b/include/llvm/Target/TargetOptions.h
@@ -67,7 +67,7 @@ namespace llvm {
HonorSignDependentRoundingFPMathOption(false),
NoZerosInBSS(false),
GuaranteedTailCallOpt(false),
- DisableTailCalls(false), StackAlignmentOverride(0),
+ StackAlignmentOverride(0),
EnableFastISel(false), PositionIndependentExecutable(false),
UseInitArray(false), DisableIntegratedAS(false),
CompressDebugSections(false), FunctionSections(false),
@@ -137,10 +137,6 @@ namespace llvm {
/// as their parent function, etc.), using an alternate ABI if necessary.
unsigned GuaranteedTailCallOpt : 1;
- /// DisableTailCalls - This flag controls whether we will use tail calls.
- /// Disabling them may be useful to maintain a correct call stack.
- unsigned DisableTailCalls : 1;
-
/// StackAlignmentOverride - Override default stack alignment for target.
unsigned StackAlignmentOverride;
@@ -236,7 +232,6 @@ inline bool operator==(const TargetOptions &LHS,
ARE_EQUAL(HonorSignDependentRoundingFPMathOption) &&
ARE_EQUAL(NoZerosInBSS) &&
ARE_EQUAL(GuaranteedTailCallOpt) &&
- ARE_EQUAL(DisableTailCalls) &&
ARE_EQUAL(StackAlignmentOverride) &&
ARE_EQUAL(EnableFastISel) &&
ARE_EQUAL(PositionIndependentExecutable) &&
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 47c8400a668..2cfbc39a05b 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -1483,9 +1483,10 @@ ARMTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
bool isStructRet = (Outs.empty()) ? false : Outs[0].Flags.isSRet();
bool isThisReturn = false;
bool isSibCall = false;
+ auto Attr = MF.getFunction()->getFnAttribute("disable-tail-calls");
// Disable tail calls if they're not supported.
- if (!Subtarget->supportsTailCall() || MF.getTarget().Options.DisableTailCalls)
+ if (!Subtarget->supportsTailCall() || Attr.getValueAsString() == "true")
isTailCall = false;
if (isTailCall) {
@@ -2375,7 +2376,9 @@ bool ARMTargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
if (!Subtarget->supportsTailCall())
return false;
- if (!CI->isTailCall() || getTargetMachine().Options.DisableTailCalls)
+ auto Attr =
+ CI->getParent()->getParent()->getFnAttribute("disable-tail-calls");
+ if (!CI->isTailCall() || Attr.getValueAsString() == "true")
return false;
return !Subtarget->isThumb1Only();
diff --git a/lib/Target/Hexagon/HexagonISelLowering.cpp b/lib/Target/Hexagon/HexagonISelLowering.cpp
index 74d92aef25a..6e9e69f5a2c 100644
--- a/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -397,7 +397,9 @@ HexagonTargetLowering::LowerReturn(SDValue Chain,
bool HexagonTargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
// If either no tail call or told not to tail call at all, don't.
- if (!CI->isTailCall() || HTM.Options.DisableTailCalls)
+ auto Attr =
+ CI->getParent()->getParent()->getFnAttribute("disable-tail-calls");
+ if (!CI->isTailCall() || Attr.getValueAsString() == "true")
return false;
return true;
@@ -486,7 +488,8 @@ HexagonTargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
else
CCInfo.AnalyzeCallOperands(Outs, CC_Hexagon);
- if (DAG.getTarget().Options.DisableTailCalls)
+ auto Attr = MF.getFunction()->getFnAttribute("disable-tail-calls");
+ if (Attr.getValueAsString() == "true")
isTailCall = false;
if (isTailCall) {
diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp
index 28242502ec8..04881264b4a 100644
--- a/lib/Target/TargetMachine.cpp
+++ b/lib/Target/TargetMachine.cpp
@@ -70,7 +70,6 @@ void TargetMachine::resetTargetOptions(const Function &F) const {
RESET_OPTION(UnsafeFPMath, "unsafe-fp-math");
RESET_OPTION(NoInfsFPMath, "no-infs-fp-math");
RESET_OPTION(NoNaNsFPMath, "no-nans-fp-math");
- RESET_OPTION(DisableTailCalls, "disable-tail-calls");
}
/// getRelocationModel - Returns the code generation relocation model. The
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index e3ec288a683..88598a1ddd0 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -2233,7 +2233,9 @@ static bool IsCCallConvention(CallingConv::ID CC) {
}
bool X86TargetLowering::mayBeEmittedAsTailCall(CallInst *CI) const {
- if (!CI->isTailCall() || getTargetMachine().Options.DisableTailCalls)
+ auto Attr =
+ CI->getParent()->getParent()->getFnAttribute("disable-tail-calls");
+ if (!CI->isTailCall() || Attr.getValueAsString() == "true")
return false;
CallSite CS(CI);
@@ -2762,8 +2764,9 @@ X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
StructReturnType SR = callIsStructReturn(Outs);
bool IsSibcall = false;
X86MachineFunctionInfo *X86Info = MF.getInfo<X86MachineFunctionInfo>();
+ auto Attr = MF.getFunction()->getFnAttribute("disable-tail-calls");
- if (MF.getTarget().Options.DisableTailCalls)
+ if (Attr.getValueAsString() == "true")
isTailCall = false;
if (Subtarget->isPICStyleGOT() &&
diff --git a/lib/Transforms/IPO/PassManagerBuilder.cpp b/lib/Transforms/IPO/PassManagerBuilder.cpp
index 3496a663f53..963f1bb13aa 100644
--- a/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -94,7 +94,6 @@ PassManagerBuilder::PassManagerBuilder() {
SizeLevel = 0;
LibraryInfo = nullptr;
Inliner = nullptr;
- DisableTailCalls = false;
DisableUnitAtATime = false;
DisableUnrollLoops = false;
BBVectorize = RunBBVectorization;
@@ -238,8 +237,7 @@ void PassManagerBuilder::populateModulePassManager(
MPM.add(createInstructionCombiningPass()); // Combine silly seq's
addExtensionsToPM(EP_Peephole, MPM);
- if (!DisableTailCalls)
- MPM.add(createTailCallEliminationPass()); // Eliminate tail calls
+ MPM.add(createTailCallEliminationPass()); // Eliminate tail calls
MPM.add(createCFGSimplificationPass()); // Merge & remove BBs
MPM.add(createReassociatePass()); // Reassociate expressions
// Rotate Loop - disable header duplication at -Oz
diff --git a/lib/Transforms/Scalar/TailRecursionElimination.cpp b/lib/Transforms/Scalar/TailRecursionElimination.cpp
index 9eef1327c3f..c7de2e2965c 100644
--- a/lib/Transforms/Scalar/TailRecursionElimination.cpp
+++ b/lib/Transforms/Scalar/TailRecursionElimination.cpp
@@ -158,6 +158,9 @@ bool TailCallElim::runOnFunction(Function &F) {
if (skipOptnoneFunction(F))
return false;
+ if (F.getFnAttribute("disable-tail-calls").getValueAsString() == "true")
+ return false;
+
bool AllCallsAreTailCalls = false;
bool Modified = markTails(F, AllCallsAreTailCalls);
if (AllCallsAreTailCalls)
diff --git a/test/CodeGen/ARM/disable-tail-calls.ll b/test/CodeGen/ARM/disable-tail-calls.ll
new file mode 100644
index 00000000000..18aa4723fd3
--- /dev/null
+++ b/test/CodeGen/ARM/disable-tail-calls.ll
@@ -0,0 +1,40 @@
+; RUN: llc < %s -march arm | FileCheck %s --check-prefix=NO-OPTION
+; RUN: llc < %s -march arm -disable-tail-calls | FileCheck %s --check-prefix=DISABLE-TRUE
+; RUN: llc < %s -march arm -disable-tail-calls=false | FileCheck %s --check-prefix=DISABLE-FALSE
+
+; Check that command line option "-disable-tail-calls" overrides function
+; attribute "disable-tail-calls".
+
+; NO-OPTION-LABEL: {{\_?}}func_attr
+; NO-OPTION: bl {{\_?}}callee
+
+; DISABLE-FALSE-LABEL: {{\_?}}func_attr
+; DISABLE-FALSE: b {{\_?}}callee
+
+; DISABLE-TRUE-LABEL: {{\_?}}func_attr
+; DISABLE-TRUE: bl {{\_?}}callee
+
+define i32 @func_attr(i32 %a) #0 {
+entry:
+ %call = tail call i32 @callee(i32 %a)
+ ret i32 %call
+}
+
+; NO-OPTION-LABEL: {{\_?}}func_noattr
+; NO-OPTION: b {{\_?}}callee
+
+; DISABLE-FALSE-LABEL: {{\_?}}func_noattr
+; DISABLE-FALSE: b {{\_?}}callee
+
+; DISABLE-TRUE-LABEL: {{\_?}}func_noattr
+; DISABLE-TRUE: bl {{\_?}}callee
+
+define i32 @func_noattr(i32 %a) {
+entry:
+ %call = tail call i32 @callee(i32 %a)
+ ret i32 %call
+}
+
+declare i32 @callee(i32)
+
+attributes #0 = { "disable-tail-calls"="true" }
diff --git a/test/CodeGen/X86/disable-tail-calls.ll b/test/CodeGen/X86/disable-tail-calls.ll
new file mode 100644
index 00000000000..80e8fd74e92
--- /dev/null
+++ b/test/CodeGen/X86/disable-tail-calls.ll
@@ -0,0 +1,40 @@
+; RUN: llc < %s -march x86-64 | FileCheck %s --check-prefix=NO-OPTION
+; RUN: llc < %s -march x86-64 -disable-tail-calls | FileCheck %s --check-prefix=DISABLE-TRUE
+; RUN: llc < %s -march x86-64 -disable-tail-calls=false | FileCheck %s --check-prefix=DISABLE-FALSE
+
+; Check that command line option "-disable-tail-calls" overrides function
+; attribute "disable-tail-calls".
+
+; NO-OPTION-LABEL: {{\_?}}func_attr
+; NO-OPTION: callq {{\_?}}callee
+
+; DISABLE-FALSE-LABEL: {{\_?}}func_attr
+; DISABLE-FALSE: jmp {{\_?}}callee
+
+; DISABLE-TRUE-LABEL: {{\_?}}func_attr
+; DISABLE-TRUE: callq {{\_?}}callee
+
+define i32 @func_attr(i32 %a) #0 {
+entry:
+ %call = tail call i32 @callee(i32 %a)
+ ret i32 %call
+}
+
+; NO-OPTION-LABEL: {{\_?}}func_noattr
+; NO-OPTION: jmp {{\_?}}callee
+
+; DISABLE-FALSE-LABEL: {{\_?}}func_noattr
+; DISABLE-FALSE: jmp {{\_?}}callee
+
+; DISABLE-TRUE-LABEL: {{\_?}}func_noattr
+; DISABLE-TRUE: callq {{\_?}}callee
+
+define i32 @func_noattr(i32 %a) {
+entry:
+ %call = tail call i32 @callee(i32 %a)
+ ret i32 %call
+}
+
+declare i32 @callee(i32)
+
+attributes #0 = { "disable-tail-calls"="true" }
--
2.34.1