Change immediates to be signed in assembly

These immediates are sign extended and usually interpreted as signed, so it's less confusing to use signed numbers. This also matches SPIKE's disassembly.

5 files changed, 162 insertions, 20 deletions

diff --git a/model/hex_bits_signed.sail b/model/hex_bits_signed.sail
new file mode 100644
index 0000000..3856d3a
--- /dev/null
+++ b/model/hex_bits_signed.sail
@@ -0,0 +1,141 @@
+/*==========================================================================*/
+/*     Sail                                                                 */
+/*                                                                          */
+/*  Sail and the Sail architecture models here, comprising all files and    */
+/*  directories except the ASL-derived Sail code in the aarch64 directory,  */
+/*  are subject to the BSD two-clause licence below.                        */
+/*                                                                          */
+/*  The ASL derived parts of the ARMv8.3 specification in                   */
+/*  aarch64/no_vector and aarch64/full are copyright ARM Ltd.               */
+/*                                                                          */
+/*  Copyright (c) 2013-2021                                                 */
+/*    Kathyrn Gray                                                          */
+/*    Shaked Flur                                                           */
+/*    Stephen Kell                                                          */
+/*    Gabriel Kerneis                                                       */
+/*    Robert Norton-Wright                                                  */
+/*    Christopher Pulte                                                     */
+/*    Peter Sewell                                                          */
+/*    Alasdair Armstrong                                                    */
+/*    Brian Campbell                                                        */
+/*    Thomas Bauereiss                                                      */
+/*    Anthony Fox                                                           */
+/*    Jon French                                                            */
+/*    Dominic Mulligan                                                      */
+/*    Stephen Kell                                                          */
+/*    Mark Wassell                                                          */
+/*    Alastair Reid (Arm Ltd)                                               */
+/*                                                                          */
+/*  All rights reserved.                                                    */
+/*                                                                          */
+/*  This work was partially supported by EPSRC grant EP/K008528/1 <a        */
+/*  href="http://www.cl.cam.ac.uk/users/pes20/rems">REMS: Rigorous          */
+/*  Engineering for Mainstream Systems</a>, an ARM iCASE award, EPSRC IAA   */
+/*  KTF funding, and donations from Arm.  This project has received         */
+/*  funding from the European Research Council (ERC) under the European     */
+/*  Union’s Horizon 2020 research and innovation programme (grant           */
+/*  agreement No 789108, ELVER).                                            */
+/*                                                                          */
+/*  This software was developed by SRI International and the University of  */
+/*  Cambridge Computer Laboratory (Department of Computer Science and       */
+/*  Technology) under DARPA/AFRL contracts FA8650-18-C-7809 ("CIFV")        */
+/*  and FA8750-10-C-0237 ("CTSRD").                                         */
+/*                                                                          */
+/*  Redistribution and use in source and binary forms, with or without      */
+/*  modification, are permitted provided that the following conditions      */
+/*  are met:                                                                */
+/*  1. Redistributions of source code must retain the above copyright       */
+/*     notice, this list of conditions and the following disclaimer.        */
+/*  2. Redistributions in binary form must reproduce the above copyright    */
+/*     notice, this list of conditions and the following disclaimer in      */
+/*     the documentation and/or other materials provided with the           */
+/*     distribution.                                                        */
+/*                                                                          */
+/*  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''      */
+/*  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED       */
+/*  TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A         */
+/*  PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR     */
+/*  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,            */
+/*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT        */
+/*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF        */
+/*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND     */
+/*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,      */
+/*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT      */
+/*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF      */
+/*  SUCH DAMAGE.                                                            */
+/*==========================================================================*/
+
+$ifndef _HEX_BITS_SIGNED
+$define _HEX_BITS_SIGNED
+
+$include <vector.sail>
+$include <string.sail>
+
+val parse_hex_bits_signed : forall 'n, 'n > 0. (int('n), string) -> bits('n)
+val valid_hex_bits_signed : forall 'n, 'n > 0. (int('n), string) -> bool
+
+val hex_bits_signed: forall 'n, 'n > 0. bits('n) <-> (int('n), string)
+
+function hex_bits_signed_forwards(bv) = {
+  if signed(bv) < 0
+  then (length(bv), concat_str("-", hex_str(unsigned(not_vec(bv) + 1))))
+  else (length(bv), hex_str(unsigned(bv)))
+}
+function hex_bits_signed_forwards_matches(bv) = true
+
+function parse_hex_bits_signed(n, str) = {
+  if string_take(str, 1) == "-"
+  then {
+    let str_ = string_drop(str, 1);
+    let bv = parse_hex_bits(n, str_);
+    not_vec(bv) + 1
+  }
+  else parse_hex_bits(n, str)
+}
+
+function valid_hex_bits_signed(n, str) = {
+  if string_take(str, 1) == "-"
+  then valid_hex_bits(n, string_drop(str, 1))
+  else valid_hex_bits(n, str)
+}
+
+function hex_bits_signed_backwards(n, str) = parse_hex_bits_signed(n, str)
+function hex_bits_signed_backwards_matches(n, str) = valid_hex_bits_signed(n, str)
+
+mapping hex_bits_signed_1 : bits(1) <-> string = { hex_bits_signed(1, s) <-> s }
+mapping hex_bits_signed_2 : bits(2) <-> string = { hex_bits_signed(2, s) <-> s }
+mapping hex_bits_signed_3 : bits(3) <-> string = { hex_bits_signed(3, s) <-> s }
+mapping hex_bits_signed_4 : bits(4) <-> string = { hex_bits_signed(4, s) <-> s }
+mapping hex_bits_signed_5 : bits(5) <-> string = { hex_bits_signed(5, s) <-> s }
+mapping hex_bits_signed_6 : bits(6) <-> string = { hex_bits_signed(6, s) <-> s }
+mapping hex_bits_signed_7 : bits(7) <-> string = { hex_bits_signed(7, s) <-> s }
+mapping hex_bits_signed_8 : bits(8) <-> string = { hex_bits_signed(8, s) <-> s }
+mapping hex_bits_signed_9 : bits(9) <-> string = { hex_bits_signed(9, s) <-> s }
+
+mapping hex_bits_signed_10 : bits(10) <-> string = { hex_bits_signed(10, s) <-> s }
+mapping hex_bits_signed_11 : bits(11) <-> string = { hex_bits_signed(11, s) <-> s }
+mapping hex_bits_signed_12 : bits(12) <-> string = { hex_bits_signed(12, s) <-> s }
+mapping hex_bits_signed_13 : bits(13) <-> string = { hex_bits_signed(13, s) <-> s }
+mapping hex_bits_signed_14 : bits(14) <-> string = { hex_bits_signed(14, s) <-> s }
+mapping hex_bits_signed_15 : bits(15) <-> string = { hex_bits_signed(15, s) <-> s }
+mapping hex_bits_signed_16 : bits(16) <-> string = { hex_bits_signed(16, s) <-> s }
+mapping hex_bits_signed_17 : bits(17) <-> string = { hex_bits_signed(17, s) <-> s }
+mapping hex_bits_signed_18 : bits(18) <-> string = { hex_bits_signed(18, s) <-> s }
+mapping hex_bits_signed_19 : bits(19) <-> string = { hex_bits_signed(19, s) <-> s }
+
+mapping hex_bits_signed_20 : bits(20) <-> string = { hex_bits_signed(20, s) <-> s }
+mapping hex_bits_signed_21 : bits(21) <-> string = { hex_bits_signed(21, s) <-> s }
+mapping hex_bits_signed_22 : bits(22) <-> string = { hex_bits_signed(22, s) <-> s }
+mapping hex_bits_signed_23 : bits(23) <-> string = { hex_bits_signed(23, s) <-> s }
+mapping hex_bits_signed_24 : bits(24) <-> string = { hex_bits_signed(24, s) <-> s }
+mapping hex_bits_signed_25 : bits(25) <-> string = { hex_bits_signed(25, s) <-> s }
+mapping hex_bits_signed_26 : bits(26) <-> string = { hex_bits_signed(26, s) <-> s }
+mapping hex_bits_signed_27 : bits(27) <-> string = { hex_bits_signed(27, s) <-> s }
+mapping hex_bits_signed_28 : bits(28) <-> string = { hex_bits_signed(28, s) <-> s }
+mapping hex_bits_signed_29 : bits(29) <-> string = { hex_bits_signed(29, s) <-> s }
+
+mapping hex_bits_signed_30 : bits(30) <-> string = { hex_bits_signed(30, s) <-> s }
+mapping hex_bits_signed_31 : bits(31) <-> string = { hex_bits_signed(31, s) <-> s }
+mapping hex_bits_signed_32 : bits(32) <-> string = { hex_bits_signed(32, s) <-> s }
+
+$endif _HEX_BITS_SIGNED
diff --git a/model/prelude.sail b/model/prelude.sail
index 028af21..5708bfa 100644
--- a/model/prelude.sail
+++ b/model/prelude.sail
@@ -17,6 +17,7 @@ $include <vector_dec.sail>
 $include <regfp.sail>
 $include <generic_equality.sail>
 $include "hex_bits.sail"
+$include "hex_bits_signed.sail"
 
 
 val not_bit : bit -> bit
diff --git a/model/riscv_insts_base.sail b/model/riscv_insts_base.sail
index 9c4630b..692cf78 100644
--- a/model/riscv_insts_base.sail
+++ b/model/riscv_insts_base.sail
@@ -37,7 +37,7 @@ mapping utype_mnemonic : uop <-> string = {
 }
 
 mapping clause assembly = UTYPE(imm, rd, op)
-  <-> utype_mnemonic(op) ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_20(imm)
+  <-> utype_mnemonic(op) ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_signed_20(imm)
 
 /* ****************************************************************** */
 union clause ast = RISCV_JAL : (bits(21), regidx)
@@ -83,7 +83,7 @@ function clause execute (RISCV_JAL(imm, rd)) = {
 /* TODO: handle 2-byte-alignment in mappings */
 
 mapping clause assembly = RISCV_JAL(imm, rd)
-  <-> "jal" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_21(imm)
+  <-> "jal" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_signed_21(imm)
 
 /* ****************************************************************** */
 union clause ast = RISCV_JALR : (bits(12), regidx, regidx)
@@ -92,7 +92,7 @@ mapping clause encdec = RISCV_JALR(imm, rs1, rd)
   <-> imm @ rs1 @ 0b000 @ rd @ 0b1100111
 
 mapping clause assembly = RISCV_JALR(imm, rs1, rd)
-  <-> "jalr" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_12(imm) ^ "(" ^ reg_name(rs1) ^ ")"
+  <-> "jalr" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_signed_12(imm) ^ "(" ^ reg_name(rs1) ^ ")"
 
 /* see riscv_jalr_seq.sail or riscv_jalr_rmem.sail for the execute clause. */
 
@@ -153,7 +153,7 @@ mapping btype_mnemonic : bop <-> string = {
 }
 
 mapping clause assembly = BTYPE(imm, rs2, rs1, op)
-  <-> btype_mnemonic(op) ^ spc() ^ reg_name(rs1) ^ sep() ^ reg_name(rs2) ^ sep() ^ hex_bits_13(imm)
+  <-> btype_mnemonic(op) ^ spc() ^ reg_name(rs1) ^ sep() ^ reg_name(rs2) ^ sep() ^ hex_bits_signed_13(imm)
 
 /* ****************************************************************** */
 union clause ast = ITYPE : (bits(12), regidx, regidx, iop)
@@ -195,7 +195,7 @@ mapping itype_mnemonic : iop <-> string = {
 }
 
 mapping clause assembly = ITYPE(imm, rs1, rd, op)
-  <-> itype_mnemonic(op) ^ spc() ^ reg_name(rd) ^ sep() ^ reg_name(rs1) ^ sep() ^ hex_bits_12(imm)
+  <-> itype_mnemonic(op) ^ spc() ^ reg_name(rd) ^ sep() ^ reg_name(rs1) ^ sep() ^ hex_bits_signed_12(imm)
 
 /* ****************************************************************** */
 union clause ast = SHIFTIOP : (bits(6), regidx, regidx, sop)
@@ -368,7 +368,7 @@ mapping maybe_u = {
 }
 
 mapping clause assembly = LOAD(imm, rs1, rd, is_unsigned, size, aq, rl)
-  <-> "l" ^ size_mnemonic(size) ^ maybe_u(is_unsigned) ^ maybe_aq(aq) ^ maybe_rl(rl) ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_12(imm) ^ "(" ^ reg_name(rs1) ^ ")"
+  <-> "l" ^ size_mnemonic(size) ^ maybe_u(is_unsigned) ^ maybe_aq(aq) ^ maybe_rl(rl) ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_signed_12(imm) ^ "(" ^ reg_name(rs1) ^ ")"
 
 /* ****************************************************************** */
 union clause ast = STORE : (bits(12), regidx, regidx, word_width, bool, bool)
@@ -421,7 +421,7 @@ function clause execute (STORE(imm, rs2, rs1, width, aq, rl)) = {
 }
 
 mapping clause assembly = STORE(imm, rs2, rs1, size, aq, rl)
-  <-> "s" ^ size_mnemonic(size) ^ maybe_aq(aq) ^ maybe_rl(rl) ^ spc() ^ reg_name(rs2) ^ sep() ^ hex_bits_12(imm) ^ opt_spc() ^ "(" ^ opt_spc() ^ reg_name(rs1) ^ opt_spc() ^ ")"
+  <-> "s" ^ size_mnemonic(size) ^ maybe_aq(aq) ^ maybe_rl(rl) ^ spc() ^ reg_name(rs2) ^ sep() ^ hex_bits_signed_12(imm) ^ opt_spc() ^ "(" ^ opt_spc() ^ reg_name(rs1) ^ opt_spc() ^ ")"
 
 /* ****************************************************************** */
 union clause ast = ADDIW : (bits(12), regidx, regidx)
@@ -439,7 +439,7 @@ function clause execute (ADDIW(imm, rs1, rd)) = {
 
 mapping clause assembly = ADDIW(imm, rs1, rd)
       if sizeof(xlen) == 64
-  <-> "addiw" ^ spc() ^ reg_name(rd) ^ sep() ^ reg_name(rs1) ^ sep() ^ hex_bits_12(imm)
+  <-> "addiw" ^ spc() ^ reg_name(rd) ^ sep() ^ reg_name(rs1) ^ sep() ^ hex_bits_signed_12(imm)
       if sizeof(xlen) == 64
 
 /* ****************************************************************** */
diff --git a/model/riscv_insts_cext.sail b/model/riscv_insts_cext.sail
index 2cf3b41..b7c63c2 100644
--- a/model/riscv_insts_cext.sail
+++ b/model/riscv_insts_cext.sail
@@ -131,7 +131,7 @@ function clause execute (C_ADDI(nzi, rsd)) = {
 
 mapping clause assembly = C_ADDI(nzi, rsd)
       if nzi != 0b000000 & rsd != zreg
-  <-> "c.addi" ^ spc() ^ reg_name(rsd) ^ sep() ^ hex_bits_6(nzi)
+  <-> "c.addi" ^ spc() ^ reg_name(rsd) ^ sep() ^ hex_bits_signed_6(nzi)
       if nzi != 0b000000 & rsd != zreg
 
 /* ****************************************************************** */
@@ -147,7 +147,7 @@ function clause execute (C_JAL(imm)) =
 
 mapping clause assembly = C_JAL(imm)
       if sizeof(xlen) == 32
-  <-> "c.jal" ^ spc() ^ hex_bits_12(imm @ 0b0)
+  <-> "c.jal" ^ spc() ^ hex_bits_signed_12(imm @ 0b0)
       if sizeof(xlen) == 32
 
 /* ****************************************************************** */
@@ -163,7 +163,7 @@ function clause execute (C_ADDIW(imm, rsd)) =
 
 mapping clause assembly = C_ADDIW(imm, rsd)
       if sizeof(xlen) == 64
-  <-> "c.addiw" ^ spc() ^ reg_name(rsd) ^ sep() ^ hex_bits_6(imm)
+  <-> "c.addiw" ^ spc() ^ reg_name(rsd) ^ sep() ^ hex_bits_signed_6(imm)
       if sizeof(xlen) == 64
 
 /* ****************************************************************** */
@@ -181,7 +181,7 @@ function clause execute (C_LI(imm, rd)) = {
 
 mapping clause assembly = C_LI(imm, rd)
       if rd != zreg
-  <-> "c.li" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_6(imm)
+  <-> "c.li" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_signed_6(imm)
       if rd != zreg
 
 /* ****************************************************************** */
@@ -199,7 +199,7 @@ function clause execute (C_ADDI16SP(imm)) = {
 
 mapping clause assembly = C_ADDI16SP(imm)
       if imm != 0b000000
-  <-> "c.addi16sp" ^ spc() ^ hex_bits_6(imm)
+  <-> "c.addi16sp" ^ spc() ^ hex_bits_signed_6(imm)
       if imm != 0b000000
 
 /* ****************************************************************** */
@@ -217,7 +217,7 @@ function clause execute (C_LUI(imm, rd)) = {
 
 mapping clause assembly = C_LUI(imm, rd)
       if rd != zreg & rd != sp & imm != 0b000000
-  <-> "c.lui" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_6(imm)
+  <-> "c.lui" ^ spc() ^ reg_name(rd) ^ sep() ^ hex_bits_signed_6(imm)
       if rd != zreg & rd != sp & imm != 0b000000
 
 /* ****************************************************************** */
@@ -268,7 +268,7 @@ function clause execute (C_ANDI(imm, rsd)) = {
 }
 
 mapping clause assembly = C_ANDI(imm, rsd)
-  <-> "c.andi" ^ spc() ^ creg_name(rsd) ^ sep() ^ hex_bits_6(imm)
+  <-> "c.andi" ^ spc() ^ creg_name(rsd) ^ sep() ^ hex_bits_signed_6(imm)
 
 /* ****************************************************************** */
 union clause ast = C_SUB : (cregidx, cregidx)
@@ -378,7 +378,7 @@ function clause execute (C_J(imm)) =
   execute(RISCV_JAL(sign_extend(imm @ 0b0), zreg))
 
 mapping clause assembly = C_J(imm)
-  <-> "c.j" ^ spc() ^ hex_bits_11(imm)
+  <-> "c.j" ^ spc() ^ hex_bits_signed_11(imm)
 
 /* ****************************************************************** */
 union clause ast = C_BEQZ : (bits(8), cregidx)
@@ -390,7 +390,7 @@ function clause execute (C_BEQZ(imm, rs)) =
   execute(BTYPE(sign_extend(imm @ 0b0), zreg, creg2reg_idx(rs), RISCV_BEQ))
 
 mapping clause assembly = C_BEQZ(imm, rs)
-  <-> "c.beqz" ^ spc() ^ creg_name(rs) ^ sep() ^ hex_bits_8(imm)
+  <-> "c.beqz" ^ spc() ^ creg_name(rs) ^ sep() ^ hex_bits_signed_8(imm)
 
 /* ****************************************************************** */
 union clause ast = C_BNEZ : (bits(8), cregidx)
@@ -402,7 +402,7 @@ function clause execute (C_BNEZ(imm, rs)) =
   execute(BTYPE(sign_extend(imm @ 0b0), zreg, creg2reg_idx(rs), RISCV_BNE))
 
 mapping clause assembly = C_BNEZ(imm, rs)
-  <-> "c.bnez" ^ spc() ^ creg_name(rs) ^ sep() ^ hex_bits_8(imm)
+  <-> "c.bnez" ^ spc() ^ creg_name(rs) ^ sep() ^ hex_bits_signed_8(imm)
 
 /* ****************************************************************** */
 union clause ast = C_SLLI : (bits(6), regidx)
diff --git a/model/riscv_insts_fext.sail b/model/riscv_insts_fext.sail
index e4afb30..fcd4bb8 100644
--- a/model/riscv_insts_fext.sail
+++ b/model/riscv_insts_fext.sail
@@ -344,7 +344,7 @@ function clause execute(LOAD_FP(imm, rs1, rd, width)) = {
 mapping clause assembly = LOAD_FP(imm, rs1, rd, width)
                       <-> "fl" ^ size_mnemonic(width)
                           ^ spc() ^ freg_or_reg_name(rd)
-                          ^ sep() ^ hex_bits_12(imm)
+                          ^ sep() ^ hex_bits_signed_12(imm)
                           ^ opt_spc() ^ "(" ^ opt_spc() ^ reg_name(rs1) ^ opt_spc() ^ ")"
 
 /* ****************************************************************** */
@@ -419,7 +419,7 @@ function clause execute (STORE_FP(imm, rs2, rs1, width)) = {
 mapping clause assembly = STORE_FP(imm, rs2, rs1, width)
                       <-> "fs" ^ size_mnemonic(width)
                           ^ spc() ^ freg_name(rs2)
-                          ^ sep() ^ hex_bits_12(imm)
+                          ^ sep() ^ hex_bits_signed_12(imm)
                           ^ opt_spc() ^ "(" ^ opt_spc() ^ reg_name(rs1) ^ opt_spc() ^ ")"
 
 /* ****************************************************************** */