Reapply "[X86] Set SHF_X86_64_LARGE for globals with explicit well-known large section name (#74381)"

This reverts commit 19fff85.

Now that explicit large globals are handled properly in the small code model.

Author: aeubanks

llvm/lib/Target/TargetMachine.cpp

@@ -61,8 +61,6 @@ bool TargetMachine::isLargeGlobalValue(const GlobalValue *GVal) const {
   // We should properly mark well-known section name prefixes as small/large,
   // because otherwise the output section may have the wrong section flags and
   // the linker will lay it out in an unexpected way.
-  // TODO: bring back lbss/ldata/lrodata checks after fixing accesses to large
-  // globals in the small code model.
   StringRef Name = GV->getSection();
   if (!Name.empty()) {
     auto IsPrefix = [&](StringRef Prefix) {
@@ -71,6 +69,8 @@ bool TargetMachine::isLargeGlobalValue(const GlobalValue *GVal) const {
     };
     if (IsPrefix(".bss") || IsPrefix(".data") || IsPrefix(".rodata"))
       return false;
+    if (IsPrefix(".lbss") || IsPrefix(".ldata") || IsPrefix(".lrodata"))
+      return true;
   }
 
   // For x86-64, we treat an explicit GlobalVariable small code model to mean

llvm/test/CodeGen/X86/code-model-elf-sections.ll

@@ -21,33 +21,33 @@
 ; SMALL: .data {{.*}} WA {{.*}}
 ; SMALL: .data.x {{.*}} WA {{.*}}
 ; SMALL: .data0 {{.*}} WA {{.*}}
-; SMALL: .ldata {{.*}} WA {{.*}}
-; SMALL: .ldata.x {{.*}} WA {{.*}}
+; SMALL: .ldata {{.*}} WAl {{.*}}
+; SMALL: .ldata.x {{.*}} WAl {{.*}}
 ; SMALL: .ldata0 {{.*}} WA {{.*}}
 ; SMALL: force_small {{.*}} WA {{.*}}
 ; SMALL: force_large {{.*}} WAl {{.*}}
 ; SMALL: foo {{.*}} WA {{.*}}
 ; SMALL: .bss {{.*}} WA {{.*}}
-; SMALL: .lbss {{.*}} WA {{.*}}
+; SMALL: .lbss {{.*}} WAl {{.*}}
 ; SMALL: .rodata {{.*}} A {{.*}}
-; SMALL: .lrodata {{.*}} A {{.*}}
+; SMALL: .lrodata {{.*}} Al {{.*}}
 ; SMALL: .data.rel.ro {{.*}} WA {{.*}}
 ; SMALL: .tbss {{.*}} WAT {{.*}}
 ; SMALL: .tdata {{.*}} WAT {{.*}}
 
 ; SMALL-DS: .data {{.*}} WA {{.*}}
 ; SMALL-DS: .data.x {{.*}} WA {{.*}}
 ; SMALL-DS: .data0 {{.*}} WA {{.*}}
-; SMALL-DS: .ldata {{.*}} WA {{.*}}
-; SMALL-DS: .ldata.x {{.*}} WA {{.*}}
+; SMALL-DS: .ldata {{.*}} WAl {{.*}}
+; SMALL-DS: .ldata.x {{.*}} WAl {{.*}}
 ; SMALL-DS: .ldata0 {{.*}} WA {{.*}}
 ; SMALL-DS: .data.data {{.*}} WA {{.*}}
 ; SMALL-DS: force_small {{.*}} WA {{.*}}
 ; SMALL-DS: force_large {{.*}} WAl {{.*}}
 ; SMALL-DS: foo {{.*}} WA {{.*}}
-; SMALL-DS: .lbss {{.*}} WA {{.*}}
+; SMALL-DS: .lbss {{.*}} WAl {{.*}}
 ; SMALL-DS: .bss.bss {{.*}} WA {{.*}}
-; SMALL-DS: .lrodata {{.*}} A {{.*}}
+; SMALL-DS: .lrodata {{.*}} Al {{.*}}
 ; SMALL-DS: .rodata.rodata {{.*}} A {{.*}}
 ; SMALL-DS: .data.rel.ro.relro {{.*}} WA {{.*}}
 ; SMALL-DS: .tbss.tbss {{.*}} WAT {{.*}}