tricore: fixed faulty conditions for extr and imask

According to the TC 1.3.1. Architecture Manual [1; page 174], results are
undefined, if pos + width > 32 and not 31 or if width = 0.

We found this error because of a different behavior between qemu-tricore
and the real tricore processor. For pos + width = 32, qemu-tricore did not
generate any intermediate code and ran into a different state compared to
the real hardware.

[1] https://www.infineon.com/dgdl/tc_v131_instructionset_v138.pdf?fileId=db3a304412b407950112b409b6dd0352

[BK: Add the why to the commit message]
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Andreas Konopik <andreas.konopik@efs-auto.de>
Signed-off-by: Georg Hofstetter <georg.hofstetter@efs-auto.de>
Signed-off-by: David Brenken <david.brenken@efs-auto.de>
Message-Id: <20210211115329.8984-2-david.brenken@efs-auto.org>
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>

diff --git a/target/tricore/translate.c b/target/tricore/translate.c
index 7752630ac14c6ce151dc4f6ecf42ffa868c3f7e5..ebeddf8f4a5719c7a69486942e00ef330d219182 100644 (file)
--- a/target/tricore/translate.c
+++ b/target/tricore/translate.c
@@ -5777,8 +5777,8 @@ static void decode_rcpw_insert(DisasContext *ctx)
     switch (op2) {
     case OPC2_32_RCPW_IMASK:
         CHECK_REG_PAIR(r2);
-        /* if pos + width > 31 undefined result */
-        if (pos + width <= 31) {
+        /* if pos + width > 32 undefined result */
+        if (pos + width <= 32) {
             tcg_gen_movi_tl(cpu_gpr_d[r2+1], ((1u << width) - 1) << pos);
             tcg_gen_movi_tl(cpu_gpr_d[r2], (const4 << pos));
         }
@@ -6999,7 +6999,7 @@ static void decode_rrpw_extract_insert(DisasContext *ctx)
 
     switch (op2) {
     case OPC2_32_RRPW_EXTR:
-        if (pos + width <= 31) {
+        if (pos + width <= 32) {
             /* optimize special cases */
             if ((pos == 0) && (width == 8)) {
                 tcg_gen_ext8s_tl(cpu_gpr_d[r3], cpu_gpr_d[r1]);
@@ -7021,7 +7021,7 @@ static void decode_rrpw_extract_insert(DisasContext *ctx)
         break;
     case OPC2_32_RRPW_IMASK:
         CHECK_REG_PAIR(r3);
-        if (pos + width <= 31) {
+        if (pos + width <= 32) {
             tcg_gen_movi_tl(cpu_gpr_d[r3+1], ((1u << width) - 1) << pos);
             tcg_gen_shli_tl(cpu_gpr_d[r3], cpu_gpr_d[r2], pos);
         }