[AArch64] Add support for got relocated LDR's

As a part of adding the tiny codemodel, we need to support ldr's with :got:
relocations on them. This seems to be mostly already done, just needs the
relocation type support.

Differential Revision: https://reviews.llvm.org/D50137


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338673 91177308-0d34-0410-b5e6-96231b3b80d8

Author: davemgreen

lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp

@@ -169,6 +169,8 @@ unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
     case AArch64::fixup_aarch64_ldr_pcrel_imm19:
       if (SymLoc == AArch64MCExpr::VK_GOTTPREL)
         return R_CLS(TLSIE_LD_GOTTPREL_PREL19);
+      if (SymLoc == AArch64MCExpr::VK_GOT)
+        return R_CLS(GOT_LD_PREL19);
       return R_CLS(LD_PREL_LO19);
     case AArch64::fixup_aarch64_pcrel_branch14:
       return R_CLS(TSTBR14);

test/MC/AArch64/arm64-elf-relocs.s

@@ -269,3 +269,10 @@ trickQuestion:
 // certainly be accepted when assembling.
    add x3, x5, :lo12:imm
 // CHECK: add x3, x5, :lo12:imm
+
+   ldr x24, #:got:sym
+   ldr d22, :got:sym
+// CHECK: ldr x24, :got:sym
+// CHECK: ldr d22, :got:sym
+// CHECK-OBJ-LP64: R_AARCH64_GOT_LD_PREL19 sym
+// CHECK-OBJ-LP64: R_AARCH64_GOT_LD_PREL19 sym

test/MC/AArch64/elf-reloc-pcreladdressing.s

@@ -7,11 +7,14 @@
         adrp x5, :got:some_label
         ldr x0, [x5, #:got_lo12:some_label]
 
+        ldr x0, :got:some_label
+
 // OBJ:      Relocations [
 // OBJ-NEXT:   Section {{.*}} .rela.text {
 // OBJ-NEXT:     0x0 R_AARCH64_ADR_PREL_LO21    some_label 0x0
 // OBJ-NEXT:     0x4 R_AARCH64_ADR_PREL_PG_HI21 some_label 0x0
 // OBJ-NEXT:     0x8 R_AARCH64_ADR_GOT_PAGE     some_label 0x0
 // OBJ-NEXT:     0xC R_AARCH64_LD64_GOT_LO12_NC some_label 0x0
+// OBJ-NEXT:     0x10 R_AARCH64_GOT_LD_PREL19   some_label 0x0
 // OBJ-NEXT:   }
 // OBJ-NEXT: ]

test/MC/AArch64/inline-asm-modifiers.s

@@ -68,13 +68,17 @@ test_inline_modifier_A:                 // @test_inline_modifier_A
 	//APP
 	adrp x0, :gottprel:var_tlsie
 	//NO_APP
+	//APP
+	ldr x0, :got:var_got
+	//NO_APP
 	ret
 .Ltmp2:
 	.size	test_inline_modifier_A, .Ltmp2-test_inline_modifier_A
 // CHECK: R_AARCH64_ADR_PREL_PG_HI21 var_simple
 // CHECK: R_AARCH64_ADR_GOT_PAGE var_got
 // CHECK: R_AARCH64_TLSDESC_ADR_PAGE21 var_tlsgd
 // CHECK: R_AARCH64_TLSIE_ADR_GOTTPREL_PAGE21 var_tlsie
+// CHECK: R_AARCH64_GOT_LD_PREL19 var_got
 
 	.globl	test_inline_modifier_wx
 	.type	test_inline_modifier_wx,@function