[Valgrind-developers] [valgrind] s390: load/store-on-condition / high-word facility related cleanups (BZ 509562)

[Florian K. <fk...@so...>]

https://sourceware.org/cgit/valgrind/commit/?id=ccbd64548f15918f04ee5ac852de6ad5fa87b6b6

commit ccbd64548f15918f04ee5ac852de6ad5fa87b6b6
Author: Florian Krohm <fl...@ei...>
Date:   Tue Nov 25 13:23:52 2025 +0000

    s390: load/store-on-condition / high-word facility related cleanups  (BZ 509562)
    
    The load/store-on-condition / high-word facility is always present on the
    supported machines.
    - Remove VEX_HWCAPS_S390X_LSC and s390_host_has_lsc
    - Update tests/s390x_features.c and none/tests/s390x/high-word
    
    Part of fixing https://bugs.kde.org/show_bug.cgi?id=509562

Diff:
---
 VEX/priv/host_s390_defs.c         | 3 +--
 VEX/priv/host_s390_defs.h         | 2 --
 VEX/priv/main_main.c              | 1 -
 VEX/pub/libvex.h                  | 4 +---
 coregrind/m_machine.c             | 1 -
 none/tests/s390x/high-word.vgtest | 1 -
 tests/s390x_features.c            | 2 --
 7 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/VEX/priv/host_s390_defs.c b/VEX/priv/host_s390_defs.c
index 948eb977e9..9482193425 100644
--- a/VEX/priv/host_s390_defs.c
+++ b/VEX/priv/host_s390_defs.c
@@ -4950,7 +4950,6 @@ s390_emit_SRXT(UChar *p, UChar r3, UChar r1, UChar r2)
 static UChar *
 s390_emit_LOCGR(UChar *p, UChar m3, UChar r1, UChar r2)
 {
-   vassert(s390_host_has_lsc);
    if (UNLIKELY(vex_traceflags & VEX_TRACE_ASM))
       S390_DISASM(XMNM("locgr", cls_disasm), GPR(r1), GPR(r2), MASK(m3));
 
@@ -9614,7 +9613,7 @@ s390_insn_cond_move_emit(UChar *buf, const s390_insn *insn)
 
    p = buf;
 
-   if (s390_host_has_lsc && hregClass(dst) == HRcInt64) {
+   if (hregClass(dst) == HRcInt64) {
       /* LOCx is not the preferred way to implement an unconditional load. */
       if (cond == S390_CC_ALWAYS) goto use_branch_insn;
 
diff --git a/VEX/priv/host_s390_defs.h b/VEX/priv/host_s390_defs.h
index f62244dcfc..b660b70776 100644
--- a/VEX/priv/host_s390_defs.h
+++ b/VEX/priv/host_s390_defs.h
@@ -918,8 +918,6 @@ VexInvalRange patchProfInc_S390(VexEndness endness_host,
 extern UInt s390_host_hwcaps;
 
 /* Convenience macros to test installed facilities */
-#define s390_host_has_lsc \
-                      (s390_host_hwcaps & (VEX_HWCAPS_S390X_LSC))
 #define s390_host_has_pfpo \
                       (s390_host_hwcaps & (VEX_HWCAPS_S390X_PFPO))
 #define s390_host_has_vx \
diff --git a/VEX/priv/main_main.c b/VEX/priv/main_main.c
index ce6f6bd112..9783d0e313 100644
--- a/VEX/priv/main_main.c
+++ b/VEX/priv/main_main.c
@@ -1902,7 +1902,6 @@ static const HChar* show_hwcaps_s390x ( UInt hwcaps )
       UInt  hwcaps_bit;
       HChar name[6];
    } hwcaps_list[] = {
-      { VEX_HWCAPS_S390X_LSC,   "lsc" },
       { VEX_HWCAPS_S390X_PFPO,  "pfpo" },
       { VEX_HWCAPS_S390X_VX,    "vx" },
       { VEX_HWCAPS_S390X_MSA5,  "msa5" },
diff --git a/VEX/pub/libvex.h b/VEX/pub/libvex.h
index 90fc9e39d5..3fcecd00fd 100644
--- a/VEX/pub/libvex.h
+++ b/VEX/pub/libvex.h
@@ -162,7 +162,6 @@ typedef
 #define VEX_S390X_MODEL_UNKNOWN  19     /* always last in list */
 #define VEX_S390X_MODEL_MASK     0x3F
 
-#define VEX_HWCAPS_S390X_LSC   (1<<16)  /* Conditional load/store facility */
 #define VEX_HWCAPS_S390X_PFPO  (1<<17)  /* Perform floating point ops facility */
 #define VEX_HWCAPS_S390X_VX    (1<<18)  /* Vector facility */
 #define VEX_HWCAPS_S390X_MSA5  (1<<19)  /* Message-security-assistance facility 5 */
@@ -177,8 +176,7 @@ typedef
 #define VEX_HWCAPS_S390X_MSA9  (1<<30)  /* Message-security-assist extension 9 */
 
 /* Special value representing all available s390x hwcaps */
-#define VEX_HWCAPS_S390X_ALL   (VEX_HWCAPS_S390X_LSC   | \
-                                VEX_HWCAPS_S390X_PFPO  | \
+#define VEX_HWCAPS_S390X_ALL   (VEX_HWCAPS_S390X_PFPO  | \
                                 VEX_HWCAPS_S390X_VX    | \
                                 VEX_HWCAPS_S390X_MSA5  | \
                                 VEX_HWCAPS_S390X_MI2   | \
diff --git a/coregrind/m_machine.c b/coregrind/m_machine.c
index b25358ba07..e285ec3d39 100644
--- a/coregrind/m_machine.c
+++ b/coregrind/m_machine.c
@@ -1565,7 +1565,6 @@ Bool VG_(machine_get_hwcaps)( void )
         UInt hwcaps_bit;
         const HChar name[6];   // may need adjustment for new facility names
      } fac_hwcaps[] = {
-        { False,  45,  VEX_HWCAPS_S390X_LSC,   "LSC"   },
         { False,  44,  VEX_HWCAPS_S390X_PFPO,  "PFPO"  },
         { False, 129,  VEX_HWCAPS_S390X_VX,    "VX"    },
         { False,  57,  VEX_HWCAPS_S390X_MSA5,  "MSA5"  },
diff --git a/none/tests/s390x/high-word.vgtest b/none/tests/s390x/high-word.vgtest
index 7c4293783a..ca27517f89 100644
--- a/none/tests/s390x/high-word.vgtest
+++ b/none/tests/s390x/high-word.vgtest
@@ -1,2 +1 @@
 prog: high-word
-prereq: ../../../tests/s390x_features 's390x-highw'
diff --git a/tests/s390x_features.c b/tests/s390x_features.c
index fa96ee8f4d..dc91ab549e 100644
--- a/tests/s390x_features.c
+++ b/tests/s390x_features.c
@@ -233,8 +233,6 @@ static int go(char *feature, char *cpu)
       match = facilities[0] & FAC_BIT(35);
    } else if (strcmp(feature, "s390x-pfpo") == 0 ) {
       match = facilities[0] & FAC_BIT(44);
-   } else if (strcmp(feature, "s390x-highw") == 0 ) {
-      match = facilities[0] & FAC_BIT(45);
    } else if (strcmp(feature, "s390x-vx") == 0 ) {
       /* VX needs kernel support; thus check the appropriate HWCAP bit. */
       match = GET_HWCAP() & 0x800;