[Stable-9.0.1 57/71] target/riscv: rvv: Fix Zvfhmin checking for vfwcvt.f.f.v and vfncvt.f.f.w instructions

[Michael Tokarev]

From: Max Chou <max.chou@sifive.com>

According v spec 18.4, only the vfwcvt.f.f.v and vfncvt.f.f.w
instructions will be affected by Zvfhmin extension.
And the vfwcvt.f.f.v and vfncvt.f.f.w instructions only support the
conversions of

* From 1*SEW(16/32) to 2*SEW(32/64)
* From 2*SEW(32/64) to 1*SEW(16/32)

Signed-off-by: Max Chou <max.chou@sifive.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Cc: qemu-stable <qemu-stable@nongnu.org>
Message-ID: <20240322092600.1198921-2-max.chou@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
(cherry picked from commit 17b713c0806e72cd8edc6c2ddd8acc5be0475df6)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/target/riscv/insn_trans/trans_rvv.c.inc 
b/target/riscv/insn_trans/trans_rvv.c.inc
index 7d84e7d812..ef568e263d 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -50,6 +50,22 @@ static bool require_rvf(DisasContext *s)
     }
 }
 
+static bool require_rvfmin(DisasContext *s)
+{
+    if (s->mstatus_fs == EXT_STATUS_DISABLED) {
+        return false;
+    }
+
+    switch (s->sew) {
+    case MO_16:
+        return s->cfg_ptr->ext_zvfhmin;
+    case MO_32:
+        return s->cfg_ptr->ext_zve32f;
+    default:
+        return false;
+    }
+}
+
 static bool require_scale_rvf(DisasContext *s)
 {
     if (s->mstatus_fs == EXT_STATUS_DISABLED) {
@@ -75,8 +91,6 @@ static bool require_scale_rvfmin(DisasContext *s)
     }
 
     switch (s->sew) {
-    case MO_8:
-        return s->cfg_ptr->ext_zvfhmin;
     case MO_16:
         return s->cfg_ptr->ext_zve32f;
     case MO_32:
@@ -2685,6 +2699,7 @@ static bool opxfv_widen_check(DisasContext *s, arg_rmr *a)
 static bool opffv_widen_check(DisasContext *s, arg_rmr *a)
 {
     return opfv_widen_check(s, a) &&
+           require_rvfmin(s) &&
            require_scale_rvfmin(s) &&
            (s->sew != MO_8);
 }
@@ -2790,6 +2805,7 @@ static bool opfxv_narrow_check(DisasContext *s, arg_rmr 
*a)
 static bool opffv_narrow_check(DisasContext *s, arg_rmr *a)
 {
     return opfv_narrow_check(s, a) &&
+           require_rvfmin(s) &&
            require_scale_rvfmin(s) &&
            (s->sew != MO_8);
 }
-- 
2.39.2