[llvm-commits] [llvm] r101965 - /llvm/trunk/lib/Target/X86/X86CodeEmitter.cpp

[Bill Wendling]

Author: void
Date: Tue Apr 20 19:34:04 2010
New Revision: 101965

URL: http://llvm.org/viewvc/llvm-project?rev=101965&view=rev
Log:
Handle a displacement location in 64-bit as an RIP-relative displacement. It
fixes a bug (<rdar://problem/7880900>) in the JIT. This code wouldn't work:

target triple = "x86_64-apple-darwin"

define double @func(double %a) {
  %tmp1 = fmul double %a, 5.000000e-01            ; <double> [#uses=1]
  ret double %tmp1
}

define i32 @main() nounwind {
  %1 = call double @func(double 4.770000e-04) ; <i64> [#uses=0]
  ret i32 0
}

Modified:
    llvm/trunk/lib/Target/X86/X86CodeEmitter.cpp

Modified: llvm/trunk/lib/Target/X86/X86CodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86CodeEmitter.cpp?rev=101965&r1=101964&r2=101965&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86CodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86CodeEmitter.cpp Tue Apr 20 19:34:04 2010
@@ -380,6 +380,16 @@
   const MachineOperand &IndexReg = MI.getOperand(Op+2);
 
   unsigned BaseReg = Base.getReg();
+  
+  // Handle %rip relative addressing.
+  if (BaseReg == X86::RIP ||
+      (Is64BitMode && DispForReloc)) { // [disp32+RIP] in X86-64 mode
+    assert(IndexReg.getReg() == 0 && Is64BitMode &&
+           "Invalid rip-relative address");
+    MCE.emitByte(ModRMByte(0, RegOpcodeField, 5));
+    emitDisplacementField(DispForReloc, DispVal, PCAdj, true);
+    return;
+  }
 
   // Indicate that the displacement will use an pcrel or absolute reference
   // by default. MCEs able to resolve addresses on-the-fly use pcrel by default
@@ -447,7 +457,7 @@
     // Emit the normal disp32 encoding.
     MCE.emitByte(ModRMByte(2, RegOpcodeField, 4));
     ForceDisp32 = true;
-  } else if (DispVal == 0 && getX86RegNum(BaseReg) != N86::EBP) {
+  } else if (DispVal == 0 && BaseRegNo != N86::EBP) {
     // Emit no displacement ModR/M byte
     MCE.emitByte(ModRMByte(0, RegOpcodeField, 4));
   } else if (isDisp8(DispVal)) {