From 693c37aa86506be657dfaf8835845b0998531c3c Mon Sep 17 00:00:00 2001
From: David Sehr <sehr@google.com>
Date: Fri, 1 Feb 2013 19:28:09 +0000
Subject: [PATCH] Two changes relevant to LEA and x32:

1) allows the use of RIP-relative addressing in 32-bit LEA instructions under
   x86-64 (ILP32 and LP64)
2) separates the size of address registers in 64-bit LEA instructions from
   control by ILP32/LP64.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174208 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86InstrArithmetic.td |  4 ++--
 lib/Target/X86/X86InstrInfo.td       | 13 +++++++++++++
 lib/Target/X86/X86MCInstLower.cpp    |  3 ++-
 test/CodeGen/X86/imul64-lea.ll       | 25 +++++++++++++++++++++++++
 test/CodeGen/X86/rip-rel-lea.ll      | 16 ++++++++++++++++
 5 files changed, 58 insertions(+), 3 deletions(-)
 create mode 100644 test/CodeGen/X86/imul64-lea.ll
 create mode 100644 test/CodeGen/X86/rip-rel-lea.ll

diff --git a/lib/Target/X86/X86InstrArithmetic.td b/lib/Target/X86/X86InstrArithmetic.td
index 0eecd5ffc12..7db611c3e1d 100644
--- a/lib/Target/X86/X86InstrArithmetic.td
+++ b/lib/Target/X86/X86InstrArithmetic.td
@@ -29,11 +29,11 @@ def LEA32r   : I<0x8D, MRMSrcMem,
 def LEA64_32r : I<0x8D, MRMSrcMem,
                   (outs GR32:$dst), (ins lea64_32mem:$src),
                   "lea{l}\t{$src|$dst}, {$dst|$src}",
-                  [(set GR32:$dst, lea32addr:$src)], IIC_LEA>,
+                  [(set GR32:$dst, lea64_32addr:$src)], IIC_LEA>,
                   Requires<[In64BitMode]>;
 
 let isReMaterializable = 1 in
-def LEA64r   : RI<0x8D, MRMSrcMem, (outs GR64:$dst), (ins i64mem:$src),
+def LEA64r   : RI<0x8D, MRMSrcMem, (outs GR64:$dst), (ins lea64mem:$src),
                   "lea{q}\t{$src|$dst}, {$dst|$src}",
                   [(set GR64:$dst, lea64addr:$src)], IIC_LEA>;
 
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 9ecf5e25c4b..0d32506a991 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -525,6 +525,13 @@ def lea64_32mem : Operand<i32> {
   let ParserMatchClass = X86MemAsmOperand;
 }
 
+// Memory operands that use 64-bit pointers in both ILP32 and LP64.
+def lea64mem : Operand<i64> {
+  let PrintMethod = "printi64mem";
+  let MIOperandInfo = (ops GR64, i8imm, GR64_NOSP, i32imm, i8imm);
+  let ParserMatchClass = X86MemAsmOperand;
+}
+
 
 //===----------------------------------------------------------------------===//
 // X86 Complex Pattern Definitions.
@@ -535,6 +542,12 @@ def addr      : ComplexPattern<iPTR, 5, "SelectAddr", [], [SDNPWantParent]>;
 def lea32addr : ComplexPattern<i32, 5, "SelectLEAAddr",
                                [add, sub, mul, X86mul_imm, shl, or, frameindex],
                                []>;
+// In 64-bit mode 32-bit LEAs can use RIP-relative addressing.
+def lea64_32addr : ComplexPattern<i32, 5, "SelectLEAAddr",
+                                  [add, sub, mul, X86mul_imm, shl, or,
+                                   frameindex, X86WrapperRIP],
+                                  []>;
+
 def tls32addr : ComplexPattern<i32, 5, "SelectTLSADDRAddr",
                                [tglobaltlsaddr], []>;
 
diff --git a/lib/Target/X86/X86MCInstLower.cpp b/lib/Target/X86/X86MCInstLower.cpp
index 5a1e1b8dc91..3af1b3e06bc 100644
--- a/lib/Target/X86/X86MCInstLower.cpp
+++ b/lib/Target/X86/X86MCInstLower.cpp
@@ -239,7 +239,8 @@ static void lower_lea64_32mem(MCInst *MI, unsigned OpNo) {
     if (!MI->getOperand(OpNo+i).isReg()) continue;
 
     unsigned Reg = MI->getOperand(OpNo+i).getReg();
-    if (Reg == 0) continue;
+    // LEAs can use RIP-relative addressing, and RIP has no sub/super register.
+    if (Reg == 0 || Reg == X86::RIP) continue;
 
     MI->getOperand(OpNo+i).setReg(getX86SubSuperRegister(Reg, MVT::i64));
   }
diff --git a/test/CodeGen/X86/imul64-lea.ll b/test/CodeGen/X86/imul64-lea.ll
new file mode 100644
index 00000000000..047c129ddb3
--- /dev/null
+++ b/test/CodeGen/X86/imul64-lea.ll
@@ -0,0 +1,25 @@
+; RUN: llc < %s -mtriple=x86_64-pc-linux-gnu | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-pc-linux-gnux32 | FileCheck %s
+
+; Test that 64-bit LEAs are generated for both LP64 and ILP32 in 64-bit mode.
+declare i64 @foo64()
+
+define i64 @test64() {
+  %tmp.0 = tail call i64 @foo64( )
+  %tmp.1 = mul i64 %tmp.0, 9
+; CHECK-NOT: mul
+; CHECK: leaq
+  ret i64 %tmp.1
+}
+
+; Test that 32-bit LEAs are generated for both LP64 and ILP32 in 64-bit mode.
+declare i32 @foo32()
+
+define i32 @test32() {
+  %tmp.0 = tail call i32 @foo32( )
+  %tmp.1 = mul i32 %tmp.0, 9
+; CHECK-NOT: mul
+; CHECK: leal
+  ret i32 %tmp.1
+}
+
diff --git a/test/CodeGen/X86/rip-rel-lea.ll b/test/CodeGen/X86/rip-rel-lea.ll
new file mode 100644
index 00000000000..71dacf60caa
--- /dev/null
+++ b/test/CodeGen/X86/rip-rel-lea.ll
@@ -0,0 +1,16 @@
+; RUN: llc < %s -mtriple=x86_64-pc-linux-gnu -relocation-model=pic | FileCheck %s -check-prefix=PIC64
+; RUN: llc < %s -mtriple=x86_64-pc-linux-gnux32 -relocation-model=pic | FileCheck %s -check-prefix=PICX32
+; RUN: llc < %s -mtriple=i686-pc-linux-gnu -relocation-model=pic | FileCheck %s -check-prefix=PIC32
+
+; Use %rip-relative addressing even in static mode on x86-64, because
+; it has a smaller encoding.
+
+@a = internal global double 3.4
+define double* @foo() nounwind {
+  %a = getelementptr double* @a, i64 0
+  ret double* %a
+  
+; PIC64:    leaq	a(%rip)
+; PICX32:   leal	a(%rip)
+; PIC32:    leal	a@GOTOFF(%eax)
+}