From a8e8c4f433fb3cce354950ba72136b84abb78015 Mon Sep 17 00:00:00 2001
From: Andreas Sandberg <andreas@sandberg.pp.se>
Date: Tue, 18 Jun 2013 16:30:06 +0200
Subject: x86: Fix loading of floating point constants

This changeset actually fixes two issues:

 * The lfpimm instruction didn't work correctly when applied to a
   floating point constant (it did work for integers containing the
   bit string representation of a constant) since it used
   reinterpret_cast to convert a double to a uint64_t. This caused a
   compilation error, at least, in gcc 4.6.3.

 * The instructions loading floating point constants in the x87
   processor didn't work correctly since they just stored a truncated
   integer instead of a double in the floating point register. This
   changeset fixes the old microcode by using lfpimm instruction
   instead of the limm instructions.
---
 src/arch/x86/isa/insts/x87/load_constants/load_0_1_or_pi.py | 6 +++---
 src/arch/x86/isa/insts/x87/load_constants/load_logarithm.py | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

(limited to 'src/arch/x86/isa/insts')

diff --git a/src/arch/x86/isa/insts/x87/load_constants/load_0_1_or_pi.py b/src/arch/x86/isa/insts/x87/load_constants/load_0_1_or_pi.py
index cb8947312..9f22af89b 100644
--- a/src/arch/x86/isa/insts/x87/load_constants/load_0_1_or_pi.py
+++ b/src/arch/x86/isa/insts/x87/load_constants/load_0_1_or_pi.py
@@ -40,17 +40,17 @@
 microcode = '''
 
 def macroop FLDZ {
-    limm ufp1, "double(0)"
+    lfpimm ufp1, 0.0
     movfp st(-1), ufp1, spm=-1
 };
 
 def macroop FLD1 {
-    limm ufp1, "double(1)"
+    lfpimm ufp1, 1.0
     movfp st(-1), ufp1, spm=-1
 };
 
 def macroop FLDPI {
-    limm ufp1, "double(3.14159265359)"
+    lfpimm ufp1, 3.14159265359
     movfp st(-1), ufp1, spm=-1
 };
 
diff --git a/src/arch/x86/isa/insts/x87/load_constants/load_logarithm.py b/src/arch/x86/isa/insts/x87/load_constants/load_logarithm.py
index 7e71c4006..88eb01086 100644
--- a/src/arch/x86/isa/insts/x87/load_constants/load_logarithm.py
+++ b/src/arch/x86/isa/insts/x87/load_constants/load_logarithm.py
@@ -40,22 +40,22 @@
 microcode = '''
 
 def macroop FLDL2E {
-    limm ufp1, "double(1.44269504089)"
+    lfpimm ufp1, 1.44269504089
     movfp st(-1), ufp1, spm=-1
 };
 
 def macroop FLDL2T {
-    limm ufp1, "double(3.32192809489)"
+    lfpimm ufp1, 3.32192809489
     movfp st(-1), ufp1, spm=-1
 };
 
 def macroop FLDLG2 {
-    limm ufp1, "double(0.30102999566)"
+    lfpimm ufp1, 0.30102999566
     movfp st(-1), ufp1, spm=-1
 };
 
 def macroop FLDLN2 {
-    limm ufp1, "double(0.69314718056)"
+    lfpimm ufp1, 0.69314718056
     movfp st(-1), ufp1, spm=-1
 };
 
-- 
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