commit 743434099d427c17f6c8f36de81a83f83ec13fb2
author Richard Henderson <rth@twiddle.net> Sat Mar 24 09:51:14 2012 -0700
committer Blue Swirl <blauwirbel@gmail.com> Sat Mar 24 17:07:58 2012 +0000
tree fb2bf1bfeaa126b9d3c786f44306c37c05ffe4e2
parent c30827555d5305d42f7b164dc69a381c4882e77a

target-alpha: Make use of fp_status.flush_inputs_to_zero.

This softfp feature post-dates the last major update to the Alpha
fpu translation.  We can make use of this to eliminate at least
one helper function that was performing this operation by hand.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

target-alpha/fpu_helper.c

diff --git a/target-alpha/fpu_helper.c b/target-alpha/fpu_helper.c
index d38521b..dda1103 100644
--- a/target-alpha/fpu_helper.c
+++ b/target-alpha/fpu_helper.c
@@ -88,21 +88,17 @@
     }
 }
 
-/* Input remapping without software completion.  Handle denormal-map-to-zero
-   and trap for all other non-finite numbers.  */
-uint64_t helper_ieee_input(CPUAlphaState *env, uint64_t val)
+/* Input handing without software completion.  Trap for all
+   non-finite numbers.  */
+void helper_ieee_input(CPUAlphaState *env, uint64_t val)
 {
     uint32_t exp = (uint32_t)(val >> 52) & 0x7ff;
     uint64_t frac = val & 0xfffffffffffffull;
 
     if (exp == 0) {
-        if (frac != 0) {
-            /* If DNZ is set flush denormals to zero on input.  */
-            if (env->fpcr_dnz) {
-                val &= 1ull << 63;
-            } else {
-                arith_excp(env, GETPC(), EXC_M_UNF, 0);
-            }
+        /* Denormals without DNZ set raise an exception.  */
+        if (frac != 0 && !env->fp_status.flush_inputs_to_zero) {
+            arith_excp(env, GETPC(), EXC_M_UNF, 0);
         }
     } else if (exp == 0x7ff) {
         /* Infinity or NaN.  */
@@ -111,43 +107,23 @@
            just emulates the insn to figure out what exception to use.  */
         arith_excp(env, GETPC(), frac ? EXC_M_INV : EXC_M_FOV, 0);
     }
-    return val;
 }
 
 /* Similar, but does not trap for infinities.  Used for comparisons.  */
-uint64_t helper_ieee_input_cmp(CPUAlphaState *env, uint64_t val)
+void helper_ieee_input_cmp(CPUAlphaState *env, uint64_t val)
 {
     uint32_t exp = (uint32_t)(val >> 52) & 0x7ff;
     uint64_t frac = val & 0xfffffffffffffull;
 
     if (exp == 0) {
-        if (frac != 0) {
-            /* If DNZ is set flush denormals to zero on input.  */
-            if (env->fpcr_dnz) {
-                val &= 1ull << 63;
-            } else {
-                arith_excp(env, GETPC(), EXC_M_UNF, 0);
-            }
+        /* Denormals without DNZ set raise an exception.  */
+        if (frac != 0 && !env->fp_status.flush_inputs_to_zero) {
+            arith_excp(env, GETPC(), EXC_M_UNF, 0);
         }
     } else if (exp == 0x7ff && frac) {
         /* NaN.  */
         arith_excp(env, GETPC(), EXC_M_INV, 0);
     }
-    return val;
-}
-
-/* Input remapping with software completion enabled.  All we have to do
-   is handle denormal-map-to-zero; all other inputs get exceptions as
-   needed from the actual operation.  */
-uint64_t helper_ieee_input_s(CPUAlphaState *env, uint64_t val)
-{
-    if (env->fpcr_dnz) {
-        uint32_t exp = (uint32_t)(val >> 52) & 0x7ff;
-        if (exp == 0) {
-            val &= 1ull << 63;
-        }
-    }
-    return val;
 }
 
 /* F floating (VAX) */