<div dir="ltr">Sure, will update.<div><br></div><div>Thanks,</div><div>Manoj</div></div><br><div class="gmail_quote"><div dir="ltr">On Fri, Apr 6, 2018 at 4:56 AM Nico Weber <<a href="mailto:thakis@chromium.org">thakis@chromium.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">This should probably get a release notes entry. Can you write one?</div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Apr 5, 2018 at 11:29 AM, Manoj Gupta via cfe-commits <span dir="ltr"><<a href="mailto:cfe-commits@lists.llvm.org" target="_blank">cfe-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: manojgupta<br>
Date: Thu Apr 5 08:29:52 2018<br>
New Revision: 329300<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=329300&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=329300&view=rev</a><br>
Log:<br>
Disable -fmerge-all-constants as default.<br>
<br>
Summary:<br>
"-fmerge-all-constants" is a non-conforming optimization and should not<br>
be the default. It is also causing miscompiles when building Linux<br>
Kernel (<a href="https://lkml.org/lkml/2018/3/20/872" rel="noreferrer" target="_blank">https://lkml.org/lkml/2018/3/20/872</a>).<br>
<br>
Fixes PR18538.<br>
<br>
Reviewers: rjmccall, rsmith, chandlerc<br>
<br>
Reviewed By: rsmith, chandlerc<br>
<br>
Subscribers: srhines, cfe-commits<br>
<br>
Differential Revision: <a href="https://reviews.llvm.org/D45289" rel="noreferrer" target="_blank">https://reviews.llvm.org/D45289</a><br>
<br>
Modified:<br>
cfe/trunk/include/clang/Driver/Options.td<br>
cfe/trunk/lib/AST/ExprConstant.cpp<br>
cfe/trunk/lib/Driver/ToolChains/Clang.cpp<br>
cfe/trunk/lib/Frontend/CompilerInvocation.cpp<br>
cfe/trunk/test/CodeGen/array-init.c<br>
cfe/trunk/test/CodeGen/decl.c<br>
cfe/trunk/test/CodeGenCXX/const-init-cxx11.cpp<br>
cfe/trunk/test/CodeGenCXX/cxx0x-initializer-references.cpp<br>
cfe/trunk/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp<br>
cfe/trunk/test/CodeGenObjCXX/<a href="http://arc-cxx11-init-list.mm" rel="noreferrer" target="_blank">arc-cxx11-init-list.mm</a><br>
cfe/trunk/test/Driver/clang_f_opts.c<br>
<br>
Modified: cfe/trunk/include/clang/Driver/Options.td<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/Options.td?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/include/clang/Driver/Options.td (original)<br>
+++ cfe/trunk/include/clang/Driver/Options.td Thu Apr 5 08:29:52 2018<br>
@@ -1133,7 +1133,8 @@ def fthinlto_index_EQ : Joined<["-"], "f<br>
HelpText<"Perform ThinLTO importing using provided function summary index">;<br>
def fmacro_backtrace_limit_EQ : Joined<["-"], "fmacro-backtrace-limit=">,<br>
Group<f_Group>, Flags<[DriverOption, CoreOption]>;<br>
-def fmerge_all_constants : Flag<["-"], "fmerge-all-constants">, Group<f_Group>;<br>
+def fmerge_all_constants : Flag<["-"], "fmerge-all-constants">, Group<f_Group>,<br>
+ Flags<[CC1Option]>, HelpText<"Allow merging of constants">;<br>
def fmessage_length_EQ : Joined<["-"], "fmessage-length=">, Group<f_Group>;<br>
def fms_extensions : Flag<["-"], "fms-extensions">, Group<f_Group>, Flags<[CC1Option, CoreOption]>,<br>
HelpText<"Accept some non-standard constructs supported by the Microsoft compiler">;<br>
@@ -1282,7 +1283,7 @@ def fveclib : Joined<["-"], "fveclib=">,<br>
def fno_lax_vector_conversions : Flag<["-"], "fno-lax-vector-conversions">, Group<f_Group>,<br>
HelpText<"Disallow implicit conversions between vectors with a different number of elements or different element types">, Flags<[CC1Option]>;<br>
def fno_merge_all_constants : Flag<["-"], "fno-merge-all-constants">, Group<f_Group>,<br>
- Flags<[CC1Option]>, HelpText<"Disallow merging of constants">;<br>
+ HelpText<"Disallow merging of constants">;<br>
def fno_modules : Flag <["-"], "fno-modules">, Group<f_Group>,<br>
Flags<[DriverOption]>;<br>
def fno_implicit_module_maps : Flag <["-"], "fno-implicit-module-maps">, Group<f_Group>,<br>
<br>
Modified: cfe/trunk/lib/AST/ExprConstant.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)<br>
+++ cfe/trunk/lib/AST/ExprConstant.cpp Thu Apr 5 08:29:52 2018<br>
@@ -8596,9 +8596,6 @@ bool IntExprEvaluator::VisitBinaryOperat<br>
(LHSValue.Base && isZeroSized(RHSValue)))<br>
return Error(E);<br>
// Pointers with different bases cannot represent the same object.<br>
- // (Note that clang defaults to -fmerge-all-constants, which can<br>
- // lead to inconsistent results for comparisons involving the address<br>
- // of a constant; this generally doesn't matter in practice.)<br>
return Success(E->getOpcode() == BO_NE, E);<br>
}<br>
<br>
<br>
Modified: cfe/trunk/lib/Driver/ToolChains/Clang.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/Clang.cpp?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/Clang.cpp?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Driver/ToolChains/Clang.cpp (original)<br>
+++ cfe/trunk/lib/Driver/ToolChains/Clang.cpp Thu Apr 5 08:29:52 2018<br>
@@ -3361,9 +3361,9 @@ void Clang::ConstructJob(Compilation &C,<br>
<br>
Args.AddLastArg(CmdArgs, options::OPT_fveclib);<br>
<br>
- if (!Args.hasFlag(options::OPT_fmerge_all_constants,<br>
- options::OPT_fno_merge_all_constants))<br>
- CmdArgs.push_back("-fno-merge-all-constants");<br>
+ if (Args.hasFlag(options::OPT_fmerge_all_constants,<br>
+ options::OPT_fno_merge_all_constants, false))<br>
+ CmdArgs.push_back("-fmerge-all-constants");<br>
<br>
// LLVM Code Generator Options.<br>
<br>
<br>
Modified: cfe/trunk/lib/Frontend/CompilerInvocation.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInvocation.cpp?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/lib/Frontend/CompilerInvocation.cpp (original)<br>
+++ cfe/trunk/lib/Frontend/CompilerInvocation.cpp Thu Apr 5 08:29:52 2018<br>
@@ -605,7 +605,7 @@ static bool ParseCodeGenArgs(CodeGenOpti<br>
Args.hasFlag(OPT_ffine_grained_bitfield_accesses,<br>
OPT_fno_fine_grained_bitfield_accesses, false);<br>
Opts.DwarfDebugFlags = Args.getLastArgValue(OPT_dwarf_debug_flags);<br>
- Opts.MergeAllConstants = !Args.hasArg(OPT_fno_merge_all_constants);<br>
+ Opts.MergeAllConstants = Args.hasArg(OPT_fmerge_all_constants);<br>
Opts.NoCommon = Args.hasArg(OPT_fno_common);<br>
Opts.NoImplicitFloat = Args.hasArg(OPT_no_implicit_float);<br>
Opts.OptimizeSize = getOptimizationLevelSize(Args);<br>
<br>
Modified: cfe/trunk/test/CodeGen/array-init.c<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/array-init.c?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/array-init.c?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/CodeGen/array-init.c (original)<br>
+++ cfe/trunk/test/CodeGen/array-init.c Thu Apr 5 08:29:52 2018<br>
@@ -1,8 +1,11 @@<br>
-// RUN: %clang_cc1 %s -O0 -triple x86_64-unknown-linux-gnu -emit-llvm -o - | FileCheck %s<br>
+// RUN: %clang_cc1 %s -O0 -triple x86_64-unknown-linux-gnu -emit-llvm -o - | FileCheck -check-prefix=CHECK-NO-MERGE-CONSTANTS %s<br>
+// RUN: %clang_cc1 %s -O0 -triple x86_64-unknown-linux-gnu -fmerge-all-constants -emit-llvm -o - | FileCheck -check-prefix=CHECK-MERGE-CONSTANTS %s<br>
<br>
-// CHECK: @{{.*}}.a1 = internal constant [5 x i32] [i32 0, i32 1, i32 2, i32 0, i32 0]<br>
-// CHECK: @{{.*}}.a2 = internal constant [5 x i32] zeroinitializer<br>
-// CHECK: @{{.*}}.a3 = internal constant [5 x i32] zeroinitializer<br>
+// CHECK-NO-MERGE-CONSTANTS: @{{.*}}.a1 = private unnamed_addr constant [5 x i32] [i32 0, i32 1, i32 2, i32 0, i32 0]<br>
+<br>
+// CHECK-MERGE-CONSTANTS: @{{.*}}.a1 = internal constant [5 x i32] [i32 0, i32 1, i32 2, i32 0, i32 0]<br>
+// CHECK-MERGE-CONSTANTS: @{{.*}}.a2 = internal constant [5 x i32] zeroinitializer<br>
+// CHECK-MERGE-CONSTANTS: @{{.*}}.a3 = internal constant [5 x i32] zeroinitializer<br>
<br>
void testConstArrayInits(void)<br>
{<br>
<br>
Modified: cfe/trunk/test/CodeGen/decl.c<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/decl.c?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/decl.c?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/CodeGen/decl.c (original)<br>
+++ cfe/trunk/test/CodeGen/decl.c Thu Apr 5 08:29:52 2018<br>
@@ -1,4 +1,4 @@<br>
-// RUN: %clang_cc1 -w -emit-llvm < %s | FileCheck %s<br>
+// RUN: %clang_cc1 -w -fmerge-all-constants -emit-llvm < %s | FileCheck %s<br>
<br>
// CHECK: @test1.x = internal constant [12 x i32] [i32 1<br>
// CHECK: @test2.x = private unnamed_addr constant [13 x i32] [i32 1,<br>
<br>
Modified: cfe/trunk/test/CodeGenCXX/const-init-cxx11.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/const-init-cxx11.cpp?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/const-init-cxx11.cpp?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/CodeGenCXX/const-init-cxx11.cpp (original)<br>
+++ cfe/trunk/test/CodeGenCXX/const-init-cxx11.cpp Thu Apr 5 08:29:52 2018<br>
@@ -1,4 +1,4 @@<br>
-// RUN: %clang_cc1 -w -triple x86_64-elf-gnu -emit-llvm -o - %s -std=c++11 | FileCheck %s<br>
+// RUN: %clang_cc1 -w -fmerge-all-constants -triple x86_64-elf-gnu -emit-llvm -o - %s -std=c++11 | FileCheck %s<br>
<br>
// FIXME: The padding in all these objects should be zero-initialized.<br>
namespace StructUnion {<br>
<br>
Modified: cfe/trunk/test/CodeGenCXX/cxx0x-initializer-references.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cxx0x-initializer-references.cpp?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cxx0x-initializer-references.cpp?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/CodeGenCXX/cxx0x-initializer-references.cpp (original)<br>
+++ cfe/trunk/test/CodeGenCXX/cxx0x-initializer-references.cpp Thu Apr 5 08:29:52 2018<br>
@@ -1,4 +1,4 @@<br>
-// RUN: %clang_cc1 -std=c++11 -S -triple armv7-none-eabi -emit-llvm -o - %s | FileCheck %s<br>
+// RUN: %clang_cc1 -std=c++11 -S -triple armv7-none-eabi -fmerge-all-constants -emit-llvm -o - %s | FileCheck %s<br>
<br>
namespace reference {<br>
struct A {<br>
<br>
Modified: cfe/trunk/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp (original)<br>
+++ cfe/trunk/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp Thu Apr 5 08:29:52 2018<br>
@@ -1,5 +1,5 @@<br>
-// RUN: %clang_cc1 -std=c++11 -triple x86_64-none-linux-gnu -emit-llvm -o - %s | FileCheck -check-prefixes=X86,CHECK %s<br>
-// RUN: %clang_cc1 -std=c++11 -triple amdgcn-amd-amdhsa -DNO_TLS -emit-llvm -o - %s | FileCheck -check-prefixes=AMDGCN,CHECK %s<br>
+// RUN: %clang_cc1 -std=c++11 -triple x86_64-none-linux-gnu -fmerge-all-constants -emit-llvm -o - %s | FileCheck -check-prefixes=X86,CHECK %s<br>
+// RUN: %clang_cc1 -std=c++11 -triple amdgcn-amd-amdhsa -DNO_TLS -fmerge-all-constants -emit-llvm -o - %s | FileCheck -check-prefixes=AMDGCN,CHECK %s<br>
<br>
namespace std {<br>
typedef decltype(sizeof(int)) size_t;<br>
<br>
Modified: cfe/trunk/test/CodeGenObjCXX/<a href="http://arc-cxx11-init-list.mm" rel="noreferrer" target="_blank">arc-cxx11-init-list.mm</a><br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjCXX/arc-cxx11-init-list.mm?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjCXX/arc-cxx11-init-list.mm?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/CodeGenObjCXX/<a href="http://arc-cxx11-init-list.mm" rel="noreferrer" target="_blank">arc-cxx11-init-list.mm</a> (original)<br>
+++ cfe/trunk/test/CodeGenObjCXX/<a href="http://arc-cxx11-init-list.mm" rel="noreferrer" target="_blank">arc-cxx11-init-list.mm</a> Thu Apr 5 08:29:52 2018<br>
@@ -1,4 +1,4 @@<br>
-// RUN: %clang_cc1 -triple armv7-ios5.0 -std=c++11 -fobjc-arc -Os -emit-llvm -o - %s | FileCheck %s<br>
+// RUN: %clang_cc1 -triple armv7-ios5.0 -std=c++11 -fmerge-all-constants -fobjc-arc -Os -emit-llvm -o - %s | FileCheck %s<br>
<br>
// CHECK: @[[STR0:.*]] = private unnamed_addr constant [5 x i8] c"str0\00", section "__TEXT,__cstring,cstring_literals"<br>
// CHECK: @[[UNNAMED_CFSTRING0:.*]] = private global %struct.__NSConstantString_tag { i32* getelementptr inbounds ([0 x i32], [0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr inbounds ([5 x i8], [5 x i8]* @[[STR0]], i32 0, i32 0), i32 4 }, section "__DATA,__cfstring"<br>
<br>
Modified: cfe/trunk/test/Driver/clang_f_opts.c<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/clang_f_opts.c?rev=329300&r1=329299&r2=329300&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/clang_f_opts.c?rev=329300&r1=329299&r2=329300&view=diff</a><br>
==============================================================================<br>
--- cfe/trunk/test/Driver/clang_f_opts.c (original)<br>
+++ cfe/trunk/test/Driver/clang_f_opts.c Thu Apr 5 08:29:52 2018<br>
@@ -276,6 +276,7 @@<br>
// RUN: -fno-inline-small-functions -finline-small-functions \<br>
// RUN: -fno-fat-lto-objects -ffat-lto-objects \<br>
// RUN: -fno-merge-constants -fmerge-constants \<br>
+// RUN: -fno-merge-all-constants -fmerge-all-constants \<br>
// RUN: -fno-caller-saves -fcaller-saves \<br>
// RUN: -fno-reorder-blocks -freorder-blocks \<br>
// RUN: -fno-schedule-insns2 -fschedule-insns2 \<br>
@@ -522,3 +523,10 @@<br>
// RUN: %clang -### -S -fno-discard-value-names %s 2>&1 | FileCheck -check-prefix=CHECK-NO-DISCARD-NAMES %s<br>
// CHECK-DISCARD-NAMES: "-discard-value-names"<br>
// CHECK-NO-DISCARD-NAMES-NOT: "-discard-value-names"<br>
+//<br>
+// RUN: %clang -### -S -fmerge-all-constants %s 2>&1 | FileCheck -check-prefix=CHECK-MERGE-ALL-CONSTANTS %s<br>
+// RUN: %clang -### -S -fno-merge-all-constants %s 2>&1 | FileCheck -check-prefix=CHECK-NO-MERGE-ALL-CONSTANTS %s<br>
+// RUN: %clang -### -S -fmerge-all-constants -fno-merge-all-constants %s 2>&1 | FileCheck -check-prefix=CHECK-NO-MERGE-ALL-CONSTANTS %s<br>
+// RUN: %clang -### -S -fno-merge-all-constants -fmerge-all-constants %s 2>&1 | FileCheck -check-prefix=CHECK-MERGE-ALL-CONSTANTS %s<br>
+// CHECK-NO-MERGE-ALL-CONSTANTS-NOT: "-fmerge-all-constants"<br>
+// CHECK-MERGE-ALL-CONSTANTS: "-fmerge-all-constants"<br>
<br>
<br>
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</blockquote></div><br></div>
</blockquote></div>