[llvm] r259528 - [MC] Enable eip-relative addressing on x86-64 for X32 ABI

[Derek Schuff via llvm-commits]

Author: dschuff
Date: Tue Feb  2 11:20:04 2016
New Revision: 259528

URL: http://llvm.org/viewvc/llvm-project?rev=259528&view=rev
Log:
[MC] Enable eip-relative addressing on x86-64 for X32 ABI

Summary:
Enables eip-based addressing, e.g.,

lea    constant(%eip), %rax
lea    constant(%eip), %eax

in MC, (used for the x32 ABI). EIP-base addressing is also valid in x86_64,
it is left enabled for that architecture as well.

Patch by João Porto

Differential Revision: http://reviews.llvm.org/D16581

Modified:
    llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
    llvm/trunk/test/MC/X86/x86-64.s

Modified: llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp?rev=259528&r1=259527&r2=259528&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp (original)
+++ llvm/trunk/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp Tue Feb  2 11:20:04 2016
@@ -231,6 +231,10 @@ static bool Is32BitMemOperand(const MCIn
       (IndexReg.getReg() != 0 &&
        X86MCRegisterClasses[X86::GR32RegClassID].contains(IndexReg.getReg())))
     return true;
+  if (BaseReg.getReg() == X86::EIP) {
+    assert(IndexReg.getReg() == 0 && "Invalid eip-based address.");
+    return true;
+  }
   return false;
 }
 
@@ -373,7 +377,8 @@ void X86MCCodeEmitter::EmitMemModRMByte(
   bool HasEVEX = (TSFlags & X86II::EncodingMask) == X86II::EVEX;
 
   // Handle %rip relative addressing.
-  if (BaseReg == X86::RIP) {    // [disp32+RIP] in X86-64 mode
+  if (BaseReg == X86::RIP ||
+      BaseReg == X86::EIP) {    // [disp32+rIP] in X86-64 mode
     assert(is64BitMode(STI) && "Rip-relative addressing requires 64-bit mode");
     assert(IndexReg.getReg() == 0 && "Invalid rip-relative address");
     EmitByte(ModRMByte(0, RegOpcodeField, 5), CurByte, OS);

Modified: llvm/trunk/test/MC/X86/x86-64.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/X86/x86-64.s?rev=259528&r1=259527&r2=259528&view=diff
==============================================================================
--- llvm/trunk/test/MC/X86/x86-64.s (original)
+++ llvm/trunk/test/MC/X86/x86-64.s Tue Feb  2 11:20:04 2016
@@ -592,6 +592,31 @@ movq	$12, foo(%rip)
 // CHECK: encoding: [0x48,0xc7,0x05,A,A,A,A,0x0c,0x00,0x00,0x00]
 // CHECK:    fixup A - offset: 3, value: foo-8, kind: reloc_riprel_4byte
 
+movl	foo(%eip), %eax
+// CHECK: movl	foo(%eip), %eax
+// CHECK: encoding: [0x67,0x8b,0x05,A,A,A,A]
+// CHECK: fixup A - offset: 3, value: foo-4, kind: reloc_riprel_4byte
+
+movb	$12, foo(%eip)
+// CHECK: movb	$12, foo(%eip)
+// CHECK: encoding: [0x67,0xc6,0x05,A,A,A,A,0x0c]
+// CHECK:    fixup A - offset: 3, value: foo-5, kind: reloc_riprel_4byte
+
+movw	$12, foo(%eip)
+// CHECK: movw	$12, foo(%eip)
+// CHECK: encoding: [0x67,0x66,0xc7,0x05,A,A,A,A,0x0c,0x00]
+// CHECK:    fixup A - offset: 4, value: foo-6, kind: reloc_riprel_4byte
+
+movl	$12, foo(%eip)
+// CHECK: movl	$12, foo(%eip)
+// CHECK: encoding: [0x67,0xc7,0x05,A,A,A,A,0x0c,0x00,0x00,0x00]
+// CHECK:    fixup A - offset: 3, value: foo-8, kind: reloc_riprel_4byte
+
+movq	$12, foo(%eip)
+// CHECK:  movq	$12, foo(%eip)
+// CHECK: encoding: [0x67,0x48,0xc7,0x05,A,A,A,A,0x0c,0x00,0x00,0x00]
+// CHECK:    fixup A - offset: 4, value: foo-8, kind: reloc_riprel_4byte
+
 // CHECK: addq	$-424, %rax
 // CHECK: encoding: [0x48,0x05,0x58,0xfe,0xff,0xff]
 addq $-424, %rax
@@ -607,6 +632,15 @@ movq _foo at GOTPCREL(%rip), %rax
 // CHECK:  fixup A - offset: 3, value: _foo at GOTPCREL-4, kind: reloc_riprel_4byte_movq_load
 movq _foo at GOTPCREL(%rip), %r14
 
+// CHECK: movq	_foo at GOTPCREL(%eip), %rax
+// CHECK:  encoding: [0x67,0x48,0x8b,0x05,A,A,A,A]
+// CHECK:  fixup A - offset: 4, value: _foo at GOTPCREL-4, kind: reloc_riprel_4byte_movq_load
+movq _foo at GOTPCREL(%eip), %rax
+
+// CHECK: movq	_foo at GOTPCREL(%eip), %r14
+// CHECK:  encoding: [0x67,0x4c,0x8b,0x35,A,A,A,A]
+// CHECK:  fixup A - offset: 4, value: _foo at GOTPCREL-4, kind: reloc_riprel_4byte_movq_load
+movq _foo at GOTPCREL(%eip), %r14
 
 // CHECK: movq	(%r13,%rax,8), %r13
 // CHECK:  encoding: [0x4d,0x8b,0x6c,0xc5,0x00]