[llvm-commits] [llvm] r96330 - in /llvm/trunk: lib/Target/X86/X86MCCodeEmitter.cpp test/MC/AsmParser/X86/x86_64-new-encoder.s

[Chris Lattner]

Author: lattner
Date: Mon Feb 15 23:03:17 2010
New Revision: 96330

URL: http://llvm.org/viewvc/llvm-project?rev=96330&view=rev
Log:
make pcrel immediate values relative to the start of the field,
not the end of the field, fixing rdar://7651978

Modified:
    llvm/trunk/lib/Target/X86/X86MCCodeEmitter.cpp
    llvm/trunk/test/MC/AsmParser/X86/x86_64-new-encoder.s

Modified: llvm/trunk/lib/Target/X86/X86MCCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86MCCodeEmitter.cpp?rev=96330&r1=96329&r2=96330&view=diff

==============================================================================
--- llvm/trunk/lib/Target/X86/X86MCCodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86MCCodeEmitter.cpp Mon Feb 15 23:03:17 2010
@@ -153,14 +153,25 @@
   // If this is a simple integer displacement that doesn't require a relocation,
   // emit it now.
   if (DispOp.isImm()) {
+    // FIXME: is this right for pc-rel encoding??  Probably need to emit this as
+    // a fixup if so.
     EmitConstant(DispOp.getImm()+ImmOffset, Size, CurByte, OS);
     return;
   }
 
   // If we have an immoffset, add it to the expression.
   const MCExpr *Expr = DispOp.getExpr();
+  
+  // If the fixup is pc-relative, we need to bias the value to be relative to
+  // the start of the field, not the end of the field.
+  if (FixupKind == MCFixupKind(X86::reloc_pcrel_4byte) ||
+      FixupKind == MCFixupKind(X86::reloc_riprel_4byte))
+    ImmOffset -= 4;
+  if (FixupKind == MCFixupKind(X86::reloc_pcrel_1byte))
+    ImmOffset -= 1;
+  
   if (ImmOffset)
-    Expr = MCBinaryExpr::CreateAdd(Expr,MCConstantExpr::Create(ImmOffset, Ctx),
+    Expr = MCBinaryExpr::CreateAdd(Expr, MCConstantExpr::Create(ImmOffset, Ctx),
                                    Ctx);
   
   // Emit a symbolic constant as a fixup and 4 zeros.
@@ -192,6 +203,7 @@
     // the size of the immediate field.  If we have this case, add it into the
     // expression to emit.
     int ImmSize = X86II::hasImm(TSFlags) ? X86II::getSizeOfImm(TSFlags) : 0;
+    
     EmitImmediate(Disp, 4, MCFixupKind(X86::reloc_riprel_4byte),
                   CurByte, OS, Fixups, -ImmSize);
     return;
@@ -616,8 +628,6 @@
   
   // If there is a remaining operand, it must be a trailing immediate.  Emit it
   // according to the right size for the instruction.
-  // FIXME: This should pass in whether the value is pc relative or not.  This
-  // information should be aquired from TSFlags as well.
   if (CurOp != NumOps)
     EmitImmediate(MI.getOperand(CurOp++),
                   X86II::getSizeOfImm(TSFlags), getImmFixupKind(TSFlags),

Modified: llvm/trunk/test/MC/AsmParser/X86/x86_64-new-encoder.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/AsmParser/X86/x86_64-new-encoder.s?rev=96330&r1=96329&r2=96330&view=diff

==============================================================================
--- llvm/trunk/test/MC/AsmParser/X86/x86_64-new-encoder.s (original)
+++ llvm/trunk/test/MC/AsmParser/X86/x86_64-new-encoder.s Mon Feb 15 23:03:17 2010
@@ -3,24 +3,24 @@
 movl	foo(%rip), %eax
 // CHECK: movl	foo(%rip), %eax
 // CHECK: encoding: [0x8b,0x05,A,A,A,A]
-// CHECK: fixup A - offset: 2, value: foo, kind: reloc_riprel_4byte
+// CHECK: fixup A - offset: 2, value: foo-4, kind: reloc_riprel_4byte
 
 movb	$12, foo(%rip)
 // CHECK: movb	$12, foo(%rip)
 // CHECK: encoding: [0xc6,0x05,A,A,A,A,0x0c]
-// CHECK:    fixup A - offset: 2, value: foo-1, kind: reloc_riprel_4byte
+// CHECK:    fixup A - offset: 2, value: foo-5, kind: reloc_riprel_4byte
 
 movw	$12, foo(%rip)
 // CHECK: movw	$12, foo(%rip)
 // CHECK: encoding: [0x66,0xc7,0x05,A,A,A,A,0x0c,0x00]
-// CHECK:    fixup A - offset: 3, value: foo-2, kind: reloc_riprel_4byte
+// CHECK:    fixup A - offset: 3, value: foo-6, kind: reloc_riprel_4byte
 
 movl	$12, foo(%rip)
 // CHECK: movl	$12, foo(%rip)
 // CHECK: encoding: [0xc7,0x05,A,A,A,A,0x0c,0x00,0x00,0x00]
-// CHECK:    fixup A - offset: 2, value: foo-4, kind: reloc_riprel_4byte
+// CHECK:    fixup A - offset: 2, value: foo-8, kind: reloc_riprel_4byte
 
 movq	$12, foo(%rip)
 // CHECK:  movq	$12, foo(%rip)
 // CHECK: encoding: [0x48,0xc7,0x05,A,A,A,A,0x0c,0x00,0x00,0x00]
-// CHECK:    fixup A - offset: 3, value: foo-4, kind: reloc_riprel_4byte
+// CHECK:    fixup A - offset: 3, value: foo-8, kind: reloc_riprel_4byte