[llvm] [llvm][SystemZ] Recognize `@GOTENT` modifier in assembler. (PR #107038)

[Alex Rønne Petersen via llvm-commits]

https://github.com/alexrp created https://github.com/llvm/llvm-project/pull/107038

Closes #105918.

I'm unsure if there are other places that need to be updated for this.

>From 5379a26fbf2bc5692687d9b6040da7dca87454c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex at alexrp.com>
Date: Tue, 3 Sep 2024 03:42:43 +0200
Subject: [PATCH] [llvm][SystemZ] Recognize @GOTENT modifier in assembler.

Closes #105918.
---
 llvm/include/llvm/MC/MCExpr.h                               | 1 +
 llvm/lib/MC/MCExpr.cpp                                      | 2 ++
 .../Target/SystemZ/MCTargetDesc/SystemZELFObjectWriter.cpp  | 1 +
 llvm/test/MC/SystemZ/fixups.s                               | 6 ++++++
 4 files changed, 10 insertions(+)

diff --git a/llvm/include/llvm/MC/MCExpr.h b/llvm/include/llvm/MC/MCExpr.h
index 118b1dd88525ab..10bc6ebd6fe506 100644
--- a/llvm/include/llvm/MC/MCExpr.h
+++ b/llvm/include/llvm/MC/MCExpr.h
@@ -192,6 +192,7 @@ class MCSymbolRefExpr : public MCExpr {
     VK_Invalid,
 
     VK_GOT,
+    VK_GOTENT,
     VK_GOTOFF,
     VK_GOTREL,
     VK_PCREL,
diff --git a/llvm/lib/MC/MCExpr.cpp b/llvm/lib/MC/MCExpr.cpp
index e4ca431c3d25f9..f04f6e8533a31b 100644
--- a/llvm/lib/MC/MCExpr.cpp
+++ b/llvm/lib/MC/MCExpr.cpp
@@ -226,6 +226,7 @@ StringRef MCSymbolRefExpr::getVariantKindName(VariantKind Kind) {
   case VK_DTPOFF: return "DTPOFF";
   case VK_DTPREL: return "DTPREL";
   case VK_GOT: return "GOT";
+  case VK_GOTENT: return "GOTENT";
   case VK_GOTOFF: return "GOTOFF";
   case VK_GOTREL: return "GOTREL";
   case VK_PCREL: return "PCREL";
@@ -407,6 +408,7 @@ MCSymbolRefExpr::getVariantKindForName(StringRef Name) {
     .Case("dtprel", VK_DTPREL)
     .Case("dtpoff", VK_DTPOFF)
     .Case("got", VK_GOT)
+    .Case("gotent", VK_GOTENT)
     .Case("gotoff", VK_GOTOFF)
     .Case("gotrel", VK_GOTREL)
     .Case("pcrel", VK_PCREL)
diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZELFObjectWriter.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZELFObjectWriter.cpp
index de1eedb8daff62..e44b4a52369153 100644
--- a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZELFObjectWriter.cpp
+++ b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZELFObjectWriter.cpp
@@ -185,6 +185,7 @@ unsigned SystemZELFObjectWriter::getRelocType(MCContext &Ctx,
     return getTLSGDReloc(Ctx, Loc, Kind);
 
   case MCSymbolRefExpr::VK_GOT:
+  case MCSymbolRefExpr::VK_GOTENT:
     if (IsPCRel && Kind == SystemZ::FK_390_PC32DBL)
       return ELF::R_390_GOTENT;
     Ctx.reportError(Loc, "Only PC-relative GOT accesses are supported for now");
diff --git a/llvm/test/MC/SystemZ/fixups.s b/llvm/test/MC/SystemZ/fixups.s
index ad0b1f18cdcfd4..0d59e60fc59579 100644
--- a/llvm/test/MC/SystemZ/fixups.s
+++ b/llvm/test/MC/SystemZ/fixups.s
@@ -19,6 +19,12 @@
 	.align 16
 	larl %r14, target at got
 
+# CHECK: larl %r14, target at GOTENT               # encoding: [0xc0,0xe0,A,A,A,A]
+# CHECK-NEXT:                                   # fixup A - offset: 2, value: target at GOTENT+2, kind: FK_390_PC32DBL
+# CHECK-REL:                                    0x{{[0-9A-F]*2}} R_390_GOTENT target 0x2
+	.align 16
+	larl %r14, target at gotent
+
 # CHECK: larl %r14, target at INDNTPOFF            # encoding: [0xc0,0xe0,A,A,A,A]
 # CHECK-NEXT:                                   # fixup A - offset: 2, value: target at INDNTPOFF+2, kind: FK_390_PC32DBL
 # CHECK-REL:                                    0x{{[0-9A-F]*2}} R_390_TLS_IEENT target 0x2