Accepting request 1007779 from devel:tools:compiler

Automatic submission by obs-autosubmit

OBS-URL: https://build.opensuse.org/request/show/1007779
OBS-URL: https://build.opensuse.org/package/show/openSUSE:Factory/llvm14?expand=0&rev=11

llvm-preserve-symbols-used.patch

@@ -0,0 +1,123 @@
+From 2cdf8f7c0bdc4d36f236e4cbb45bd9f996f15d14 Mon Sep 17 00:00:00 2001
+From: Amanieu d'Antras <amanieu@gmail.com>
+Date: Thu, 16 Jun 2022 21:31:33 +0100
+Subject: [PATCH 1/8] [MergeFunctions] Preserve symbols used
+ llvm.used/llvm.compiler.used
+
+llvm.used and llvm.compiler.used are often used with inline assembly
+that refers to a specific symbol so that the symbol is kept through to
+the linker even though there are no references to it from LLVM IR.
+
+This fixes the MergeFunctions pass to preserve references to these
+symbols in llvm.used/llvm.compiler.used so they are not deleted from the
+IR. This doesn't prevent these functions from being merged, but
+guarantees that an alias or thunk with the expected symbol name is kept
+in the IR.
+
+Differential Revision: https://reviews.llvm.org/D127751
+
+(cherry picked from commit caa2a829cdf905a5e8664d96a464d414b2adb42e)
+---
+ llvm/lib/Transforms/IPO/MergeFunctions.cpp   | 15 ++++++++-
+ llvm/test/Transforms/MergeFunc/merge-used.ll | 35 ++++++++++++++++++++
+ 2 files changed, 49 insertions(+), 1 deletion(-)
+ create mode 100644 llvm/test/Transforms/MergeFunc/merge-used.ll
+
+diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+index 97ef872c5499..b51e0a5d4dce 100644
+--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
++++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+@@ -123,6 +123,7 @@
+ #include "llvm/Transforms/IPO.h"
+ #include "llvm/Transforms/IPO/MergeFunctions.h"
+ #include "llvm/Transforms/Utils/FunctionComparator.h"
++#include "llvm/Transforms/Utils/ModuleUtils.h"
+ #include <algorithm>
+ #include <cassert>
+ #include <iterator>
+@@ -228,6 +229,9 @@ private:
+   /// analyzed again.
+   std::vector<WeakTrackingVH> Deferred;
+ 
++  /// Set of values marked as used in llvm.used and llvm.compiler.used.
++  SmallPtrSet<GlobalValue *, 4> Used;
++
+ #ifndef NDEBUG
+   /// Checks the rules of order relation introduced among functions set.
+   /// Returns true, if sanity check has been passed, and false if failed.
+@@ -410,6 +414,11 @@ static bool isEligibleForMerging(Function &F) {
+ bool MergeFunctions::runOnModule(Module &M) {
+   bool Changed = false;
+ 
++  SmallVector<GlobalValue *, 4> UsedV;
++  collectUsedGlobalVariables(M, UsedV, /*CompilerUsed=*/false);
++  collectUsedGlobalVariables(M, UsedV, /*CompilerUsed=*/true);
++  Used.insert(UsedV.begin(), UsedV.end());
++
+   // All functions in the module, ordered by hash. Functions with a unique
+   // hash value are easily eliminated.
+   std::vector<std::pair<FunctionComparator::FunctionHash, Function *>>
+@@ -456,6 +465,7 @@ bool MergeFunctions::runOnModule(Module &M) {
+   FnTree.clear();
+   FNodesInTree.clear();
+   GlobalNumbers.clear();
++  Used.clear();
+ 
+   return Changed;
+ }
+@@ -828,7 +838,10 @@ void MergeFunctions::mergeTwoFunctions(Function *F, Function *G) {
+     // For better debugability, under MergeFunctionsPDI, we do not modify G's
+     // call sites to point to F even when within the same translation unit.
+     if (!G->isInterposable() && !MergeFunctionsPDI) {
+-      if (G->hasGlobalUnnamedAddr()) {
++      // Functions referred to by llvm.used/llvm.compiler.used are special:
++      // there are uses of the symbol name that are not visible to LLVM,
++      // usually from inline asm.
++      if (G->hasGlobalUnnamedAddr() && !Used.contains(G)) {
+         // G might have been a key in our GlobalNumberState, and it's illegal
+         // to replace a key in ValueMap<GlobalValue *> with a non-global.
+         GlobalNumbers.erase(G);
+diff --git a/llvm/test/Transforms/MergeFunc/merge-used.ll b/llvm/test/Transforms/MergeFunc/merge-used.ll
+new file mode 100644
+index 000000000000..a86e66eee3f9
+--- /dev/null
++++ b/llvm/test/Transforms/MergeFunc/merge-used.ll
+@@ -0,0 +1,35 @@
++; RUN: opt -S -mergefunc < %s | FileCheck %s
++
++@llvm.compiler.used = appending global [1 x i8*] [i8* bitcast (i32 (i32)* @a to i8*)], section "llvm.metadata"
++
++define internal i32 @a(i32 %a) unnamed_addr {
++  %b = xor i32 %a, 0
++  %c = xor i32 %b, 0
++  ret i32 %c
++}
++
++define i32 @b(i32 %a) unnamed_addr {
++  %b = xor i32 %a, 0
++  %c = xor i32 %b, 0
++  ret i32 %c
++}
++
++define i32 @c(i32 %a) unnamed_addr {
++  %b = tail call i32 @a(i32 %a)
++  ret i32 %b
++}
++
++; CHECK-LABEL: @llvm.compiler.used = appending global [1 x i8*] [i8* bitcast (i32 (i32)* @a to i8*)], section "llvm.metadata"
++
++; CHECK-LABEL: define i32 @b(i32 %a) unnamed_addr
++; CHECK-NEXT:    xor
++; CHECK-NEXT:    xor
++; CHECK-NEXT:    ret
++
++; CHECK-LABEL: define i32 @c(i32 %a) unnamed_addr
++; CHECK-NEXT:    tail call i32 @b(i32 %a)
++; CHECK-NEXT:    ret
++
++; CHECK-LABEL: define internal i32 @a(i32 %0) unnamed_addr
++; CHECK-NEXT:    tail call i32 @b(i32 %0)
++; CHECK-NEXT:    ret
+-- 
+2.37.0 (Apple Git-136)
+

llvm14.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Sep 27 03:23:10 UTC 2022 - William Brown <william.brown@suse.com>
+
+- Add llvm-preserve-symbols-used.patch to resolve some symbols preserving
+  with asm in Rust.
+
 -------------------------------------------------------------------
 Wed Sep 21 21:21:19 UTC 2022 - Aaron Puchert <aaronpuchert@alice-dsl.net>
 

llvm14.spec

@@ -377,6 +377,8 @@ Patch34:        clang-repl-private-deps.patch
 Patch35:        llvm-glibc-2-36.patch
 # Let test match for linux instead of -linux-.
 Patch36:        clang-test-xfail-gnuless-triple.patch
+# Cherry pick from rust llvm project (https://reviews.llvm.org/D127751)
+Patch37:        llvm-preserve-symbols-used.patch
 BuildRequires:  binutils-devel >= 2.21.90
 BuildRequires:  cmake >= 3.13.4
 BuildRequires:  fdupes
@@ -806,6 +808,7 @@ This package contains the development files for Polly.
 %patch25 -p2
 %patch27 -p2
 %patch33 -p2
+%patch37 -p2
 
 pushd clang-%{_version}.src
 %patch2 -p1