[PATCH] D103988: SampleFDO] place the discriminator flag variable into the used list.

[Rong Xu via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rG434fed5aff5e: [SampleFDO] Using common linkage for the discriminator flag variable (authored by xur).
Herald added a subscriber: pengfei.

Changed prior to commit:
  https://reviews.llvm.org/D103988?vs=351549&id=352257#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103988/new/

https://reviews.llvm.org/D103988

Files:
  llvm/lib/CodeGen/MIRFSDiscriminator.cpp
  llvm/test/CodeGen/X86/fsafdo_test1.ll
  llvm/test/CodeGen/X86/fsafdo_test2.ll


Index: llvm/test/CodeGen/X86/fsafdo_test2.ll
===================================================================
--- llvm/test/CodeGen/X86/fsafdo_test2.ll
+++ llvm/test/CodeGen/X86/fsafdo_test2.ll
@@ -43,12 +43,8 @@
 ; CHECK: .loc    1 23 9 is_stmt 0 discriminator 3623878657 # unroll.c:23:9
 ;;
 ;; Check that variable __llvm_fs_discriminator__ is generated.
-; CHECK: .type   __llvm_fs_discriminator__, at object # @__llvm_fs_discriminator__
-; CHECK: .section        .rodata,"a", at progbits
-; CHECK: .weak   __llvm_fs_discriminator__
-; CHECK: __llvm_fs_discriminator__:
-; CHECK: .byte   1
-; CHECK: .size   __llvm_fs_discriminator__, 1
+; CHECK: .type   __llvm_fs_discriminator__, at object
+; CHECK: .comm __llvm_fs_discriminator__,1,1
 
 target triple = "x86_64-unknown-linux-gnu"
 
Index: llvm/test/CodeGen/X86/fsafdo_test1.ll
===================================================================
--- llvm/test/CodeGen/X86/fsafdo_test1.ll
+++ llvm/test/CodeGen/X86/fsafdo_test1.ll
@@ -1,17 +1,13 @@
 ; RUN: llc -enable-fs-discriminator < %s | FileCheck %s
 ;
-; Check that fs-afdo discriminators are generated.
+;; Check that fs-afdo discriminators are generated.
 ; CHECK: .loc    1 7 3 is_stmt 0 discriminator 2 # foo.c:7:3
 ; Check: .loc    1 9 5 is_stmt 1 discriminator 2 # foo.c:9:5
 ; CHECK: .loc    1 9 5 is_stmt 0 discriminator 268435458 # foo.c:9:5
 ; CHECK: .loc    1 7 3 is_stmt 1 discriminator 3892314114 # foo.c:7:3
-; Check that variable __llvm_fs_discriminator__ is generated.
-; CHECK: .type   __llvm_fs_discriminator__, at object # @__llvm_fs_discriminator__
-; CHECK: .section        .rodata,"a", at progbits
-; CHECK: .weak   __llvm_fs_discriminator__
-; CHECK: __llvm_fs_discriminator__:
-; CHECK: .byte   1
-; CHECK: .size   __llvm_fs_discriminator__, 1
+;; Check that variable __llvm_fs_discriminator__ is generated.
+; CHECK: .type   __llvm_fs_discriminator__, at object
+; CHECK: .comm __llvm_fs_discriminator__,1,1
 
 target triple = "x86_64-unknown-linux-gnu"
 
Index: llvm/lib/CodeGen/MIRFSDiscriminator.cpp
===================================================================
--- llvm/lib/CodeGen/MIRFSDiscriminator.cpp
+++ llvm/lib/CodeGen/MIRFSDiscriminator.cpp
@@ -132,9 +132,10 @@
     if (!M->getGlobalVariable(FSDiscriminatorVar)) {
       auto &Context = M->getContext();
       // Create a global variable to flag that FSDiscriminators are used.
-      new GlobalVariable(*M, Type::getInt1Ty(Context), true,
-                         GlobalValue::WeakAnyLinkage,
-                         ConstantInt::getTrue(Context), FSDiscriminatorVar);
+      // Using "common" linkage so that it will not gc GC'ed.
+      new GlobalVariable(*M, Type::getInt1Ty(Context), false,
+                         GlobalValue::CommonLinkage,
+                         ConstantInt::getFalse(Context), FSDiscriminatorVar);
     }
 
     LLVM_DEBUG(dbgs() << "Num of FS Discriminators: " << NumNewD << "\n");


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D103988.352257.patch
Type: text/x-patch
Size: 2910 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20210615/0be322fb/attachment.bin>