From 65a7a6f7a3a9fc5fd2e50200c81a6ec00a78ffd3 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sat, 11 Jul 2009 23:17:29 +0000
Subject: fix x86-64 static codegen to materialize the address of a global with
 movl instead of lea.  It is better for code size (and presumably efficiency)
 to use:

  movl $foo, %eax

rather than:

  leal foo, eax

Both give a nice zero extending "move immediate" instruction, the former is just
smaller.  Note that global addresses should be handled different by the x86
backend, but I chose to follow the style already in place and add more fixme's.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75403 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86Instr64bit.td | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

(limited to 'lib')

diff --git a/lib/Target/X86/X86Instr64bit.td b/lib/Target/X86/X86Instr64bit.td
index 2fe26c0b70..ba886e45ac 100644
--- a/lib/Target/X86/X86Instr64bit.td
+++ b/lib/Target/X86/X86Instr64bit.td
@@ -45,9 +45,8 @@ def lea64_32mem : Operand<i32> {
 // Complex Pattern Definitions.
 //
 def lea64addr : ComplexPattern<i64, 4, "SelectLEAAddr",
-                        [add, mul, X86mul_imm, shl, or, frameindex, X86Wrapper,
-                         X86WrapperRIP],
-                        []>;
+                        [add, mul, X86mul_imm, shl, or, frameindex,
+                         X86WrapperRIP], []>;
 
 def tls64addr : ComplexPattern<i64, 4, "SelectTLSADDRAddr",
                                [tglobaltlsaddr], []>;
@@ -1421,6 +1420,19 @@ def : Pat<(i64 (X86Wrapper tglobaladdr :$dst)),
 def : Pat<(i64 (X86Wrapper texternalsym:$dst)),
           (MOV64ri texternalsym:$dst)>, Requires<[NotSmallCode]>;
 
+// In static codegen with small code model, we can get the address of a label
+// into a register with 'movl'.  FIXME: This is a hack, the 'imm' predicate of
+// the MOV64ri64i32 should accept these.
+def : Pat<(i64 (X86Wrapper tconstpool  :$dst)),
+          (MOV64ri64i32 tconstpool  :$dst)>, Requires<[SmallCode]>;
+def : Pat<(i64 (X86Wrapper tjumptable  :$dst)),
+          (MOV64ri64i32 tjumptable  :$dst)>, Requires<[SmallCode]>;
+def : Pat<(i64 (X86Wrapper tglobaladdr :$dst)),
+          (MOV64ri64i32 tglobaladdr :$dst)>, Requires<[SmallCode]>;
+def : Pat<(i64 (X86Wrapper texternalsym:$dst)),
+          (MOV64ri64i32 texternalsym:$dst)>, Requires<[SmallCode]>;
+
+
 // If we have small model and -static mode, it is safe to store global addresses
 // directly as immediates.  FIXME: This is really a hack, the 'imm' predicate
 // for MOV64mi32 should handle this sort of thing.
-- 
cgit v1.2.3-70-g09d2