[arch-commits] Commit in lib32-llvm/trunk (5 files)

Evangelos Foutras foutrelis at archlinux.org
Thu May 27 04:22:13 UTC 2021


    Date: Thursday, May 27, 2021 @ 04:22:12
  Author: foutrelis
Revision: 947986

upgpkg: lib32-llvm 12.0.0-1: new upstream release

Build with -fno-semantic-interposition and -Bsymbolic-function
for improved performance (FS#70697).

Added:
  lib32-llvm/trunk/add-fno-semantic-interposition.patch
  lib32-llvm/trunk/force-visibility-of-llvm-Any-to-external.patch
  lib32-llvm/trunk/llvm-link-with-Bsymbolic-functions.patch
Modified:
  lib32-llvm/trunk/PKGBUILD
Deleted:
  lib32-llvm/trunk/amdgpu-avoid-an-illegal-operand-in-si-shrink-instr.patch

----------------------------------------------------------+
 PKGBUILD                                                 |   22 ++-
 add-fno-semantic-interposition.patch                     |   22 +++
 amdgpu-avoid-an-illegal-operand-in-si-shrink-instr.patch |   85 -------------
 force-visibility-of-llvm-Any-to-external.patch           |   42 ++++++
 llvm-link-with-Bsymbolic-functions.patch                 |   66 ++++++++++
 5 files changed, 145 insertions(+), 92 deletions(-)

Modified: PKGBUILD
===================================================================
--- PKGBUILD	2021-05-27 04:21:53 UTC (rev 947985)
+++ PKGBUILD	2021-05-27 04:22:12 UTC (rev 947986)
@@ -3,7 +3,7 @@
 # Contributor: Jan "heftig" Steffens <jan.steffens at gmail.com>
 
 pkgname=('lib32-llvm' 'lib32-llvm-libs')
-pkgver=11.1.0
+pkgver=12.0.0
 pkgrel=1
 arch=('x86_64')
 url="https://llvm.org/"
@@ -13,10 +13,14 @@
 options=('staticlibs')
 _source_base=https://github.com/llvm/llvm-project/releases/download/llvmorg-$pkgver
 source=($_source_base/llvm-$pkgver.src.tar.xz{,.sig}
-        amdgpu-avoid-an-illegal-operand-in-si-shrink-instr.patch)
-sha256sums=('ce8508e318a01a63d4e8b3090ab2ded3c598a50258cc49e2625b9120d4c03ea5'
+        force-visibility-of-llvm-Any-to-external.patch
+        llvm-link-with-Bsymbolic-functions.patch
+        add-fno-semantic-interposition.patch)
+sha256sums=('49dc47c8697a1a0abd4ee51629a696d7bfe803662f2a7252a3b16fc75f3a8b50'
             'SKIP'
-            '85b6977005899bc76fcc548e0b6501cae5f50a8ad03060b9f58d03d775323327')
+            '98721af5a36af2a8e88c14a81b16d3929b12515d7d2d1ba385eb243dca3c32cb'
+            '560ce1e206c19f4b86f4c583b743db0ad47a610418999350710aafd60ae50fcd'
+            'fc8c64267a5d179e9fc24fb2bc6150edef2598c83f5b2d138d14e05ce9f4e345')
 validpgpkeys+=('B6C8F98282B944E3B0D5C2530FC3042E345AD05D') # Hans Wennborg <hans at chromium.org>
 validpgpkeys+=('474E22316ABF4785A88C6E8EA2C794A986419D8A') # Tom Stellard <tstellar at redhat.com>
 
@@ -24,9 +28,13 @@
   cd "$srcdir/llvm-$pkgver.src"
   mkdir build
 
-  # https://gitlab.freedesktop.org/mesa/mesa/-/issues/4107
-  # https://bugs.llvm.org/show_bug.cgi?id=48921#c2
-  patch -Np2 -i ../amdgpu-avoid-an-illegal-operand-in-si-shrink-instr.patch
+  # https://bugs.llvm.org/show_bug.cgi?id=48992
+  patch -Np2 -i ../force-visibility-of-llvm-Any-to-external.patch
+
+  # https://bugs.archlinux.org/task/70697
+  patch -Np2 -i ../llvm-link-with-Bsymbolic-functions.patch
+  # https://reviews.llvm.org/D102453
+  patch -Np2 -i ../add-fno-semantic-interposition.patch
 }
 
 build() {

Added: add-fno-semantic-interposition.patch
===================================================================
--- add-fno-semantic-interposition.patch	                        (rev 0)
+++ add-fno-semantic-interposition.patch	2021-05-27 04:22:12 UTC (rev 947986)
@@ -0,0 +1,22 @@
+diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
+--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
++++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
+@@ -305,6 +305,17 @@
+     # On Windows all code is PIC. MinGW warns if -fPIC is used.
+   else()
+     add_flag_or_print_warning("-fPIC" FPIC)
++    # Enable interprocedural optimizations for non-inline functions which would
++    # otherwise be disabled due to GCC -fPIC's default.
++    #
++    # Note: Clang allows IPO for -fPIC so this optimization is less effective.
++    # Older Clang may support -fno-semantic-interposition but it used local
++    # aliases to optimize global variables, which is incompatible with copy
++    # relocations due to -fno-pic.
++    if (CMAKE_COMPILER_IS_GNUCXX OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND
++        CMAKE_CXX_COMPILER_VERSION GREATER_EQUAL 13))
++      add_flag_if_supported("-fno-semantic-interposition" FNO_SEMANTIC_INTERPOSITION)
++    endif()
+   endif()
+   # GCC for MIPS can miscompile LLVM due to PR37701.
+   if(CMAKE_COMPILER_IS_GNUCXX AND LLVM_NATIVE_ARCH STREQUAL "Mips" AND
+

Deleted: amdgpu-avoid-an-illegal-operand-in-si-shrink-instr.patch
===================================================================
--- amdgpu-avoid-an-illegal-operand-in-si-shrink-instr.patch	2021-05-27 04:21:53 UTC (rev 947985)
+++ amdgpu-avoid-an-illegal-operand-in-si-shrink-instr.patch	2021-05-27 04:22:12 UTC (rev 947986)
@@ -1,85 +0,0 @@
-commit b08a140a8fe8d0b0d16a93042b4952d6e34ab913
-Author: Piotr Sobczak <Piotr.Sobczak at amd.com>
-Date:   Wed Jan 27 16:02:49 2021 +0100
-
-    [AMDGPU] Avoid an illegal operand in si-shrink-instructions
-    
-    Before the patch it was possible to trigger a constant bus
-    violation when folding immediates into a shrunk instruction.
-    
-    The patch adds a check to enforce the legality of the new operand.
-    
-    Differential Revision: https://reviews.llvm.org/D95527
-
-diff --git a/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp b/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp
-index 9c6833a7dab6..6c1b16eddc84 100644
---- a/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp
-+++ b/llvm/lib/Target/AMDGPU/SIShrinkInstructions.cpp
-@@ -84,21 +84,23 @@ static bool foldImmediates(MachineInstr &MI, const SIInstrInfo *TII,
-         MachineOperand &MovSrc = Def->getOperand(1);
-         bool ConstantFolded = false;
- 
--        if (MovSrc.isImm() && (isInt<32>(MovSrc.getImm()) ||
--                               isUInt<32>(MovSrc.getImm()))) {
--          // It's possible to have only one component of a super-reg defined by
--          // a single mov, so we need to clear any subregister flag.
--          Src0.setSubReg(0);
--          Src0.ChangeToImmediate(MovSrc.getImm());
--          ConstantFolded = true;
--        } else if (MovSrc.isFI()) {
--          Src0.setSubReg(0);
--          Src0.ChangeToFrameIndex(MovSrc.getIndex());
--          ConstantFolded = true;
--        } else if (MovSrc.isGlobal()) {
--          Src0.ChangeToGA(MovSrc.getGlobal(), MovSrc.getOffset(),
--                          MovSrc.getTargetFlags());
--          ConstantFolded = true;
-+        if (TII->isOperandLegal(MI, Src0Idx, &MovSrc)) {
-+          if (MovSrc.isImm() &&
-+              (isInt<32>(MovSrc.getImm()) || isUInt<32>(MovSrc.getImm()))) {
-+            // It's possible to have only one component of a super-reg defined
-+            // by a single mov, so we need to clear any subregister flag.
-+            Src0.setSubReg(0);
-+            Src0.ChangeToImmediate(MovSrc.getImm());
-+            ConstantFolded = true;
-+          } else if (MovSrc.isFI()) {
-+            Src0.setSubReg(0);
-+            Src0.ChangeToFrameIndex(MovSrc.getIndex());
-+            ConstantFolded = true;
-+          } else if (MovSrc.isGlobal()) {
-+            Src0.ChangeToGA(MovSrc.getGlobal(), MovSrc.getOffset(),
-+                            MovSrc.getTargetFlags());
-+            ConstantFolded = true;
-+          }
-         }
- 
-         if (ConstantFolded) {
-diff --git a/llvm/test/CodeGen/AMDGPU/shrink-instructions-illegal-fold.mir b/llvm/test/CodeGen/AMDGPU/shrink-instructions-illegal-fold.mir
-new file mode 100644
-index 000000000000..7889f437facf
---- /dev/null
-+++ b/llvm/test/CodeGen/AMDGPU/shrink-instructions-illegal-fold.mir
-@@ -0,0 +1,23 @@
-+# RUN: llc -march=amdgcn -mcpu=gfx900 -run-pass=si-shrink-instructions --verify-machineinstrs %s -o - | FileCheck %s
-+
-+# Make sure immediate folding into V_CNDMASK respects constant bus restrictions.
-+---
-+
-+name:            shrink_cndmask_illegal_imm_folding
-+tracksRegLiveness: true
-+body:             |
-+  bb.0:
-+    liveins: $vgpr0, $vgpr1
-+    ; CHECK-LABEL: name: shrink_cndmask_illegal_imm_folding
-+    ; CHECK: [[COPY:%[0-9]+]]:vgpr_32 = COPY $vgpr0
-+    ; CHECK: [[MOV:%[0-9]+]]:vgpr_32 = V_MOV_B32_e32 32768, implicit $exec
-+    ; CHECK: V_CMP_EQ_U32_e32 0, [[COPY]], implicit-def $vcc, implicit $exec
-+    ; CHECK: V_CNDMASK_B32_e32 [[MOV]], killed [[COPY]], implicit $vcc, implicit $exec
-+
-+    %0:vgpr_32 = COPY $vgpr0
-+    %1:vgpr_32 = V_MOV_B32_e32 32768, implicit $exec
-+    V_CMP_EQ_U32_e32 0, %0:vgpr_32, implicit-def $vcc, implicit $exec
-+    %2:vgpr_32 = V_CNDMASK_B32_e64 0, %1:vgpr_32, 0, killed %0:vgpr_32, $vcc, implicit $exec
-+    S_NOP 0
-+
-+...

Added: force-visibility-of-llvm-Any-to-external.patch
===================================================================
--- force-visibility-of-llvm-Any-to-external.patch	                        (rev 0)
+++ force-visibility-of-llvm-Any-to-external.patch	2021-05-27 04:22:12 UTC (rev 947986)
@@ -0,0 +1,42 @@
+From 3d3abc22b3ef189813a3b9061c2a90ba86a32f44 Mon Sep 17 00:00:00 2001
+From: serge-sans-paille <sguelton at redhat.com>
+Date: Tue, 11 May 2021 20:46:58 +0200
+Subject: [PATCH] Force visibility of llvm::Any to external
+
+llvm::Any::TypeId::Id relies on the uniqueness of the address of a static
+variable defined in a template function. hidden visibility implies vague linkage
+for that variable, which does not guarantee the uniqueness of the address across
+a binary and a shared library. This totally breaks the implementation of
+llvm::Any.
+
+Ideally, setting visibility to llvm::Any::TypeId::Id should be enough,
+unfortunately this doesn't work as expected and we lack time (before 12.0.1
+release) to understand why setting the visibility to llvm::Any does work.
+
+See https://gcc.gnu.org/wiki/Visibility and
+https://gcc.gnu.org/onlinedocs/gcc/Vague-Linkage.html
+for more information on that topic.
+
+Differential Revision: https://reviews.llvm.org/D101972
+---
+ llvm/include/llvm/ADT/Any.h | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/llvm/include/llvm/ADT/Any.h b/llvm/include/llvm/ADT/Any.h
+index 15b114f7932d..e513586845a1 100644
+--- a/llvm/include/llvm/ADT/Any.h
++++ b/llvm/include/llvm/ADT/Any.h
+@@ -23,7 +23,12 @@
+ 
+ namespace llvm {
+ 
+-class Any {
++class LLVM_EXTERNAL_VISIBILITY Any {
++
++  // The `Typeid<T>::Id` static data member below is a globally unique
++  // identifier for the type `T`. It is explicitly marked with default
++  // visibility so that when `-fvisibility=hidden` is used, the loader still
++  // merges duplicate definitions across DSO boundaries.
+   template <typename T> struct TypeId { static const char Id; };
+ 
+   struct StorageBase {

Added: llvm-link-with-Bsymbolic-functions.patch
===================================================================
--- llvm-link-with-Bsymbolic-functions.patch	                        (rev 0)
+++ llvm-link-with-Bsymbolic-functions.patch	2021-05-27 04:22:12 UTC (rev 947986)
@@ -0,0 +1,66 @@
+From 4f05f4c8e66bc76b1d94f5283494404382e3bacd Mon Sep 17 00:00:00 2001
+From: Fangrui Song <i at maskray.me>
+Date: Thu, 13 May 2021 13:44:57 -0700
+Subject: [PATCH] [CMake][ELF] Link libLLVM.so and libclang-cpp.so with
+ -Bsymbolic-functions
+
+llvm-dev message: https://lists.llvm.org/pipermail/llvm-dev/2021-May/150465.html
+
+In an ELF shared object, a default visibility defined symbol is preemptible by
+default. This creates some missed optimization opportunities.
+-Bsymbolic-functions is more aggressive than our current -fvisibility-inlines-hidden
+(present since 2012) as it applies to all function definitions.  It can
+
+* avoid PLT for cross-TU function calls && reduce dynamic symbol lookup
+* reduce dynamic symbol lookup for taking function addresses and optimize out GOT/TOC on x86-64/ppc64
+
+In a -DLLVM_TARGETS_TO_BUILD=X86 build, the number of JUMP_SLOT decreases from 12716 to 1628, and the number of GLOB_DAT decreases from 1918 to 1313
+The built clang with `-DLLVM_LINK_LLVM_DYLIB=on -DCLANG_LINK_CLANG_DYLIB=on` is significantly faster.
+See the Linux kernel build result https://bugs.archlinux.org/task/70697
+
+Note: the performance of -fno-semantic-interposition -Bsymbolic-functions
+libLLVM.so and libclang-cpp.so is close to a PIE binary linking against
+`libLLVM*.a` and `libclang*.a`. When the host compiler is Clang,
+-Bsymbolic-functions is the major contributor.  On x86-64 (with GOTPCRELX) and
+ppc64 ELFv2, the GOT/TOC relocations can be optimized.
+
+Some implication:
+
+Interposing a subset of functions is no longer supported.
+(This is fragile on ELF and unsupported on Mach-O at all. For Mach-O we don't
+use `ld -interpose` or `-flat_namespace`)
+
+Compiling a program which takes the address of any LLVM function with
+`{gcc,clang} -fno-pic` and expects the address to equal to the address taken
+from libLLVM.so or libclang-cpp.so is unsupported. I am fairly confident that
+llvm-project shouldn't have different behaviors depending on such pointer
+equality (as we've been using -fvisibility-inlines-hidden which applies to
+inline functions for a long time), but if we accidentally do, users should be
+aware that they should not make assumption on pointer equality in `-fno-pic`
+mode.
+
+See more on https://maskray.me/blog/2021-05-09-fno-semantic-interposition
+
+Reviewed By: phosek
+
+Differential Revision: https://reviews.llvm.org/D102090
+---
+ llvm/tools/llvm-shlib/CMakeLists.txt | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/llvm/tools/llvm-shlib/CMakeLists.txt b/llvm/tools/llvm-shlib/CMakeLists.txt
+index b0ee19049e6f..03e1383ec8b4 100644
+--- a/llvm/tools/llvm-shlib/CMakeLists.txt
++++ b/llvm/tools/llvm-shlib/CMakeLists.txt
+@@ -50,6 +50,11 @@ if(LLVM_BUILD_LLVM_DYLIB)
+       # Solaris ld does not accept global: *; so there is no way to version *all* global symbols
+       set(LIB_NAMES -Wl,--version-script,${LLVM_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map ${LIB_NAMES})
+     endif()
++    # Optimize function calls for default visibility definitions to avoid PLT and
++    # reduce dynamic relocations.
++    # Note: for -fno-pic default, the address of a function may be different from
++    # inside and outside libLLVM.so.
++    target_link_options(LLVM PRIVATE LINKER:-Bsymbolic-functions)
+   elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
+     set(LIB_NAMES -Wl,-all_load ${LIB_NAMES})
+   endif()



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