From: Florian Krohm <flo2030@eich-krohm.de>
Date: Tue, 23 Sep 2025 20:29:19 +0000 (+0000)
Subject: s390: Add missing BFP rounding mode conversions
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d8cf0a84b26ff1ed1b5a9560bfbe5bf476f10c3a;p=thirdparty%2Fvalgrind.git

s390: Add missing BFP rounding mode conversions

Function decode_bfp_rounding_mode:
- Irrm_NEAREST_TIE_AWAY_0 --> S390_BFP_ROUND_NEAREST_AWAY
- Irrm_PREPARE_SHORTER    --> S390_BFP_ROUND_PREPARE_SHORT

Macros S390_CC_FOR_BFP_CONVERT, S390_CC_FOR_BFP_UCONVERT
- add S390_BFP_ROUND_NEAREST_AWAY
- add S390_BFP_ROUND_PREPARE_SHORT

Macros S390_CC_FOR_BFP128_CONVERT, S390_CC_FOR_BFP128_UCONVERT
- add S390_BFP_ROUND_NEAREST_AWAY
- add S390_BFP_ROUND_PREPARE_SHORT

Fix more out-of-date comments related to rounding.
---

diff --git a/VEX/priv/guest_s390_helpers.c b/VEX/priv/guest_s390_helpers.c
index 5bfd5eb3f..4fd9daf41 100644
--- a/VEX/priv/guest_s390_helpers.c
+++ b/VEX/priv/guest_s390_helpers.c
@@ -628,7 +628,7 @@ s390_do_cu12_cu14_helper2(UInt byte1, UInt byte2, UInt byte3, UInt byte4,
       UInt ij     = (byte3 >> 4) & 0x3;
       UInt klmn   = byte3 & 0xf;
       UInt opqrst = byte4 & 0x3f;
-      
+
       if (is_cu12) {
          UInt abcd = (uvwxy - 1) & 0xf;
          UInt high_surrogate = (0xd8 << 8) | (abcd << 6) | (efgh << 2) | ij;
@@ -782,6 +782,8 @@ decode_bfp_rounding_mode(UInt irrm)
    case Irrm_NegINF:  return S390_BFP_ROUND_NEGINF;
    case Irrm_PosINF:  return S390_BFP_ROUND_POSINF;
    case Irrm_ZERO:    return S390_BFP_ROUND_ZERO;
+   case Irrm_NEAREST_TIE_AWAY_0: return S390_BFP_ROUND_NEAREST_AWAY;
+   case Irrm_PREPARE_SHORTER:    return S390_BFP_ROUND_PREPARE_SHORT;
    }
    vpanic("decode_bfp_rounding_mode");
 }
@@ -880,6 +882,12 @@ decode_bfp_rounding_mode(UInt irrm)
 ({                                                        \
    UInt cc;                                               \
    switch (decode_bfp_rounding_mode(cc_dep2)) {           \
+   case S390_BFP_ROUND_NEAREST_AWAY:                      \
+      cc = S390_CC_FOR_BFP_CONVERT_AUX(opcode,cc_dep1,1); \
+      break;                                              \
+   case S390_BFP_ROUND_PREPARE_SHORT:                     \
+      cc = S390_CC_FOR_BFP_CONVERT_AUX(opcode,cc_dep1,3); \
+      break;                                              \
    case S390_BFP_ROUND_NEAREST_EVEN:                      \
       cc = S390_CC_FOR_BFP_CONVERT_AUX(opcode,cc_dep1,4); \
       break;                                              \
@@ -914,6 +922,12 @@ decode_bfp_rounding_mode(UInt irrm)
 ({                                                         \
    UInt cc;                                                \
    switch (decode_bfp_rounding_mode(cc_dep2)) {            \
+   case S390_BFP_ROUND_NEAREST_AWAY:                       \
+      cc = S390_CC_FOR_BFP_UCONVERT_AUX(opcode,cc_dep1,1); \
+      break;                                               \
+   case S390_BFP_ROUND_PREPARE_SHORT:                      \
+      cc = S390_CC_FOR_BFP_UCONVERT_AUX(opcode,cc_dep1,3); \
+      break;                                               \
    case S390_BFP_ROUND_NEAREST_EVEN:                       \
       cc = S390_CC_FOR_BFP_UCONVERT_AUX(opcode,cc_dep1,4); \
       break;                                               \
@@ -951,6 +965,12 @@ decode_bfp_rounding_mode(UInt irrm)
       s390_cc_thunk_put3 for rationale. */                           \
    cc_dep2 = cc_dep2 ^ cc_ndep;                                      \
    switch (decode_bfp_rounding_mode(cc_ndep)) {                      \
+   case S390_BFP_ROUND_NEAREST_AWAY:                                 \
+      cc = S390_CC_FOR_BFP128_CONVERT_AUX(opcode,cc_dep1,cc_dep2,1); \
+      break;                                                         \
+   case S390_BFP_ROUND_PREPARE_SHORT:                                \
+      cc = S390_CC_FOR_BFP128_CONVERT_AUX(opcode,cc_dep1,cc_dep2,3); \
+      break;                                                         \
    case S390_BFP_ROUND_NEAREST_EVEN:                                 \
       cc = S390_CC_FOR_BFP128_CONVERT_AUX(opcode,cc_dep1,cc_dep2,4); \
       break;                                                         \
@@ -988,6 +1008,13 @@ decode_bfp_rounding_mode(UInt irrm)
       s390_cc_thunk_put3 for rationale. */                            \
    cc_dep2 = cc_dep2 ^ cc_ndep;                                       \
    switch (decode_bfp_rounding_mode(cc_ndep)) {                       \
+   case S390_BFP_ROUND_NEAREST_AWAY:                                  \
+      cc = S390_CC_FOR_BFP128_UCONVERT_AUX(opcode,cc_dep1,cc_dep2,1); \
+      break;                                                          \
+   case S390_BFP_ROUND_PREPARE_SHORT:                                 \
+      cc = S390_CC_FOR_BFP128_UCONVERT_AUX(opcode,cc_dep1,cc_dep2,3); \
+      cc = S390_CC_FOR_BFP_UCONVERT_AUX(opcode,cc_dep1,3);            \
+      break;                                                          \
    case S390_BFP_ROUND_NEAREST_EVEN:                                  \
       cc = S390_CC_FOR_BFP128_UCONVERT_AUX(opcode,cc_dep1,cc_dep2,4); \
       break;                                                          \
diff --git a/none/tests/s390x/rounding.h b/none/tests/s390x/rounding.h
index 34555a8d8..63f19a723 100644
--- a/none/tests/s390x/rounding.h
+++ b/none/tests/s390x/rounding.h
@@ -8,14 +8,11 @@
 /* instructions (e.g. CFEBR)                                        */
 /* ---------------------------------------------------------------- */
 #define M3_BFP_ROUND_PER_FPC        0
-
-// Cannot be mapped to IRRoundingMode
 #define M3_BFP_ROUND_NEAREST_AWAY   1
 
 // 2 is not allowed
 
 // Needs floating point extension facility
-// Cannot be mapped to IRRoundingMode
 #define M3_BFP_ROUND_PREPARE_SHORT  3
 
 #define M3_BFP_ROUND_NEAREST_EVEN   4