From 6dbde11f5a46550784eb4d288b765c4339cf3c4c Mon Sep 17 00:00:00 2001
From: florian <florian@freepascal.org>
Date: Sat, 17 Nov 2018 15:08:22 +0000
Subject: [PATCH] * three operand shl for shifting by 2, 4 or 8 can be
 simulated by lea

git-svn-id: trunk@40337 -
---
 compiler/x86/cgx86.pas | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/compiler/x86/cgx86.pas b/compiler/x86/cgx86.pas
index a1c02656f6..fc6a488d0f 100644
--- a/compiler/x86/cgx86.pas
+++ b/compiler/x86/cgx86.pas
@@ -2080,6 +2080,14 @@ unit cgx86;
             reference_reset_base(href,src,al,ctempposinvalid,0,[]);
             list.concat(taicpu.op_ref_reg(A_LEA,TCgSize2OpSize[size],href,dst));
           end
+        else if (op=OP_SHL) and (size in [OS_32,OS_S32,OS_64,OS_S64]) and
+          (int64(a)>=1) and (int64(a)<=3) then
+          begin
+            reference_reset_base(href,NR_NO,0,ctempposinvalid,0,[]);
+            href.index:=src;
+            href.scalefactor:=1 shl longint(a);
+            list.concat(taicpu.op_ref_reg(A_LEA,TCgSize2OpSize[size],href,dst));
+          end
         else if (op=OP_SUB) and
           ((size in [OS_32,OS_S32]) or
            { lea supports only 32 bit signed displacments }