[llvm] r258308 - [AArch64] Fix two bugs in the .inst directive

[Oliver Stannard via llvm-commits]

Author: olista01
Date: Wed Jan 20 06:54:31 2016
New Revision: 258308

URL: http://llvm.org/viewvc/llvm-project?rev=258308&view=rev
Log:
[AArch64] Fix two bugs in the .inst directive

The AArch64 .inst directive was implemented using EmitIntValue, which resulted
in both $x and $d (code and data) mapping symbols being emitted at the same
address. This fixes it to only emit the $x mapping symbol.

EmitIntValue also emits the value in big-endian order when targeting big-endian
systems, but instructions are always emitted in little-endian order for
AArch64.

Differential Revision: http://reviews.llvm.org/D16349


Modified:
    llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64ELFStreamer.cpp
    llvm/trunk/test/MC/AArch64/inst-directive.s

Modified: llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64ELFStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64ELFStreamer.cpp?rev=258308&r1=258307&r2=258308&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64ELFStreamer.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/MCTargetDesc/AArch64ELFStreamer.cpp Wed Jan 20 06:54:31 2016
@@ -112,9 +112,21 @@ public:
     MCELFStreamer::EmitInstruction(Inst, STI);
   }
 
+  /// Emit a 32-bit value as an instruction. This is only used for the .inst
+  /// directive, EmitInstruction should be used in other cases.
   void emitInst(uint32_t Inst) {
+    char Buffer[4];
+
+    // We can't just use EmitIntValue here, as that will emit a data mapping
+    // symbol, and swap the endianness on big-endian systems (instructions are
+    // always little-endian).
+    for (unsigned I = 0; I < 4; ++I) {
+      Buffer[I] = uint8_t(Inst);
+      Inst >>= 8;
+    }
+
     EmitA64MappingSymbol();
-    MCELFStreamer::EmitIntValue(Inst, 4);
+    MCELFStreamer::EmitBytes(StringRef(Buffer, 4));
   }
 
   /// This is one of the functions used to emit data into an ELF section, so the

Modified: llvm/trunk/test/MC/AArch64/inst-directive.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AArch64/inst-directive.s?rev=258308&r1=258307&r2=258308&view=diff
==============================================================================
--- llvm/trunk/test/MC/AArch64/inst-directive.s (original)
+++ llvm/trunk/test/MC/AArch64/inst-directive.s Wed Jan 20 06:54:31 2016
@@ -1,7 +1,14 @@
 // RUN: llvm-mc %s -triple=aarch64-none-linux-gnu -filetype=asm -o - \
 // RUN:   | FileCheck %s --check-prefix=CHECK-ASM
-// RUN: llvm-mc %s -triple=aarch64-none-linux-gnu -filetype=obj -o - \
-// RUN:   | llvm-readobj -s -sd | FileCheck %s  --check-prefix=CHECK-OBJ
+// RUN: llvm-mc %s -triple=aarch64-none-linux-gnu -filetype=obj -o %t
+// RUN: llvm-readobj -s -sd %t | FileCheck %s  --check-prefix=CHECK-OBJ
+// RUN: llvm-objdump -t %t | FileCheck %s  --check-prefix=CHECK-SYMS
+
+// RUN: llvm-mc %s -triple=aarch64_be-none-linux-gnu -filetype=asm -o - \
+// RUN:   | FileCheck %s --check-prefix=CHECK-ASM
+// RUN: llvm-mc %s -triple=aarch64_be-none-linux-gnu -filetype=obj -o %t
+// RUN: llvm-readobj -s -sd %t | FileCheck %s  --check-prefix=CHECK-OBJ
+// RUN: llvm-objdump -t %t | FileCheck %s  --check-prefix=CHECK-SYMS
 
     .section    .inst.aarch64_inst
 
@@ -22,3 +29,7 @@ aarch64_inst:
 // CHECK-OBJ:   SectionData (
 // CHECK-OBJ-NEXT: 0000: 2040105E
 // CHECK-OBJ-NEXT: )
+
+// CHECK-SYMS-NOT: 0000000000000000         .inst.aarch64_inst              00000000 $d
+// CHECK-SYMS:     0000000000000000         .inst.aarch64_inst              00000000 $x
+// CHECK-SYMS-NOT: 0000000000000000         .inst.aarch64_inst              00000000 $d