From 27100972beac69743e10285ec42b363ad8046f8b Mon Sep 17 00:00:00 2001
From: Sandipan Das <sandipan@linux.vnet.ibm.com>
Date: Thu, 7 Jun 2018 11:11:11 +0530
Subject: [PATCH] arch-power: Add fixed-point word arithmetic modulo
 instructions

This adds the following arithmetic instructions:
  * Modulo Signed Word (modsw)
  * Modulo Unsigned Word (moduw)

Change-Id: I5590e569afb71dd429c473bd18c65457e2c49286
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
---
 src/arch/power/isa/decoder.isa         | 24 +++++++++++++++++++++++-
 src/arch/power/isa/formats/integer.isa | 13 ++++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/arch/power/isa/decoder.isa b/src/arch/power/isa/decoder.isa
index ff9f62a06..052d68c83 100644
--- a/src/arch/power/isa/decoder.isa
+++ b/src/arch/power/isa/decoder.isa
@@ -378,6 +378,28 @@ decode PO default Unknown::unknown() {
             181: stdux({{ Mem = Rs; }});
         }
 
+        format IntArithOp {
+            779: modsw({{
+                int64_t src1 = Ra_sw;
+                int64_t src2 = Rb_sw;
+                if ((src1 != INT32_MIN || src2 != -1) && src2 != 0) {
+                    Rt = src1 % src2;
+                } else {
+                    Rt = 0;
+                }
+            }});
+
+            267: moduw({{
+                uint64_t src1 = Ra_uw;
+                uint64_t src2 = Rb_uw;
+                if (src2 != 0) {
+                    Rt = src1 % src2;
+                } else {
+                    Rt = 0;
+                }
+            }});
+        }
+
         format IntOp {
             0: cmp({{
                 Xer xer = XER;
@@ -559,7 +581,7 @@ decode PO default Unknown::unknown() {
 
             // Arithmetic instructions all use source registers Ra and Rb,
             // with destination register Rt.
-            format IntArithOp {
+            format IntArithCheckRcOp {
                 75: mulhw({{
                     uint64_t res = (int64_t)Ra_sw * Rb_sw;
                     res = res >> 32;
diff --git a/src/arch/power/isa/formats/integer.isa b/src/arch/power/isa/formats/integer.isa
index 928c3d3c8..ca679c267 100644
--- a/src/arch/power/isa/formats/integer.isa
+++ b/src/arch/power/isa/formats/integer.isa
@@ -322,6 +322,17 @@ def format IntSumOp(src1, src2, ca = {{ 0 }}, computeCA = 0,
 }};
 
 
+// Instructions that use source registers Ra and Rb, with the result
+// placed into Rt but do not check for carry, overflow or the Rc bit.
+def format IntArithOp(code, inst_flags = []) {{
+
+    # Generate the class
+    (header_output, decoder_output, decode_block, exec_output) = \
+        GenAluOp(name, Name, 'IntArithOp', code, inst_flags, BasicDecode,
+                 BasicConstructor)
+}};
+
+
 // Instructions that use source registers Ra and Rb, with the result
 // placed into Rt. Basically multiply and divide instructions. The
 // carry bit is never set, but overflow can be calculated. In certain
@@ -332,7 +343,7 @@ def format IntSumOp(src1, src2, ca = {{ 0 }}, computeCA = 0,
 // each instruction to deal with different combinations of having the
 // OE bit set or unset and the Rc bit set or unset too. Otherwise, we
 // generate two versions of each instruction to deal with the Rc bit.
-def format IntArithOp(code, computeOV = 0, inst_flags = []) {{
+def format IntArithCheckRcOp(code, computeOV = 0, inst_flags = []) {{
 
     # The result is always in Rt, but the source values vary
     dict = {'result':'Rt', 'inputa':'src1', 'inputb':'src2'}
-- 
2.30.2