[PULL 03/28] target/alpha: Fix SWCR_TRAP_ENABLE_MASK

["Alex Bennée" <alex.bennee@linaro.org>]

From: Richard Henderson <richard.henderson@linaro.org>

The CONFIG_USER_ONLY adjustment blindly mashed the swcr
exception enable bits into the fpcr exception disable bits.

However, fpcr_exc_enable has already converted the exception
disable bits into the exception status bits in order to make
it easier to mask status bits at runtime.

Instead, merge the swcr enable bits with the fpcr before we
convert to status bits.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190921043256.4575-4-richard.henderson@linaro.org>

diff --git a/target/alpha/helper.c b/target/alpha/helper.c
index 10602fb339..e21c488aa3 100644
--- a/target/alpha/helper.c
+++ b/target/alpha/helper.c
@@ -46,34 +46,39 @@ void cpu_alpha_store_fpcr(CPUAlphaState *env, uint64_t val)
     uint32_t fpcr = val >> 32;
     uint32_t t = 0;
 
+    /* Record the raw value before adjusting for linux-user.  */
+    env->fpcr = fpcr;
+
+#ifdef CONFIG_USER_ONLY
+    /*
+     * Override some of these bits with the contents of ENV->SWCR.
+     * In system mode, some of these would trap to the kernel, at
+     * which point the kernel's handler would emulate and apply
+     * the software exception mask.
+     */
+    uint32_t soft_fpcr = alpha_ieee_swcr_to_fpcr(env->swcr) >> 32;
+    fpcr |= soft_fpcr & FPCR_STATUS_MASK;
+#endif
+
     t |= CONVERT_BIT(fpcr, FPCR_INED, FPCR_INE);
     t |= CONVERT_BIT(fpcr, FPCR_UNFD, FPCR_UNF);
     t |= CONVERT_BIT(fpcr, FPCR_OVFD, FPCR_OVF);
     t |= CONVERT_BIT(fpcr, FPCR_DZED, FPCR_DZE);
     t |= CONVERT_BIT(fpcr, FPCR_INVD, FPCR_INV);
 
-    env->fpcr = fpcr;
     env->fpcr_exc_enable = ~t & FPCR_STATUS_MASK;
 
     env->fpcr_dyn_round = rm_map[(fpcr & FPCR_DYN_MASK) >> FPCR_DYN_SHIFT];
 
     env->fpcr_flush_to_zero = (fpcr & FPCR_UNFD) && (fpcr & FPCR_UNDZ);
     env->fp_status.flush_inputs_to_zero = (fpcr & FPCR_DNZ) != 0;
-
 #ifdef CONFIG_USER_ONLY
-    /*
-     * Override some of these bits with the contents of ENV->SWCR.
-     * In system mode, some of these would trap to the kernel, at
-     * which point the kernel's handler would emulate and apply
-     * the software exception mask.
-     */
     if (env->swcr & SWCR_MAP_DMZ) {
         env->fp_status.flush_inputs_to_zero = 1;
     }
     if (env->swcr & SWCR_MAP_UMZ) {
         env->fpcr_flush_to_zero = 1;
     }
-    env->fpcr_exc_enable &= ~(alpha_ieee_swcr_to_fpcr(env->swcr) >> 32);
 #endif
 }
 
-- 
2.20.1