[Qemu-devel] [6034] target-ppc: fix fcmp{o,u} instructions

[Aurelien Jarno]

Revision: 6034
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6034
Author:   aurel32
Date:     2008-12-14 19:34:09 +0000 (Sun, 14 Dec 2008)

Log Message:
-----------
target-ppc: fix fcmp{o,u} instructions

The instructions are specified to update the condition register even if
an error is to be signaled because of NaN input.

Signed-off-by: Nathan Froyd <address@hidden>
Signed-off-by: Aurelien Jarno <address@hidden>

Modified Paths:
--------------
    trunk/target-ppc/helper.h
    trunk/target-ppc/op_helper.c
    trunk/target-ppc/translate.c

Modified: trunk/target-ppc/helper.h
===================================================================
--- trunk/target-ppc/helper.h   2008-12-14 18:59:08 UTC (rev 6033)
+++ trunk/target-ppc/helper.h   2008-12-14 19:34:09 UTC (rev 6034)
@@ -63,8 +63,8 @@
 DEF_HELPER_1(float64_to_float32, i32, i64)
 DEF_HELPER_1(float32_to_float64, i64, i32)
 
-DEF_HELPER_2(fcmpo, i32, i64, i64)
-DEF_HELPER_2(fcmpu, i32, i64, i64)
+DEF_HELPER_3(fcmpo, void, i64, i64, i32)
+DEF_HELPER_3(fcmpu, void, i64, i64, i32)
 
 DEF_HELPER_1(fctiw, i64, i64)
 DEF_HELPER_1(fctiwz, i64, i64)

Modified: trunk/target-ppc/op_helper.c
===================================================================
--- trunk/target-ppc/op_helper.c        2008-12-14 18:59:08 UTC (rev 6033)
+++ trunk/target-ppc/op_helper.c        2008-12-14 19:34:09 UTC (rev 6034)
@@ -1620,32 +1620,36 @@
         return arg3;
 }
 
-uint32_t helper_fcmpu (uint64_t arg1, uint64_t arg2)
+void helper_fcmpu (uint64_t arg1, uint64_t arg2, uint32_t crfD)
 {
     CPU_DoubleU farg1, farg2;
     uint32_t ret = 0;
     farg1.ll = arg1;
     farg2.ll = arg2;
 
-    if (unlikely(float64_is_signaling_nan(farg1.d) ||
-                 float64_is_signaling_nan(farg2.d))) {
-        /* sNaN comparison */
-        fload_invalid_op_excp(POWERPC_EXCP_FP_VXSNAN);
+    if (unlikely(float64_is_nan(farg1.d) ||
+                 float64_is_nan(farg2.d))) {
+        ret = 0x01UL;
+    } else if (float64_lt(farg1.d, farg2.d, &env->fp_status)) {
+        ret = 0x08UL;
+    } else if (!float64_le(farg1.d, farg2.d, &env->fp_status)) {
+        ret = 0x04UL;
     } else {
-        if (float64_lt(farg1.d, farg2.d, &env->fp_status)) {
-            ret = 0x08UL;
-        } else if (!float64_le(farg1.d, farg2.d, &env->fp_status)) {
-            ret = 0x04UL;
-        } else {
-            ret = 0x02UL;
-        }
+        ret = 0x02UL;
     }
+
     env->fpscr &= ~(0x0F << FPSCR_FPRF);
     env->fpscr |= ret << FPSCR_FPRF;
-    return ret;
+    env->crf[crfD] = ret;
+    if (unlikely(ret == 0x01UL
+                 && (float64_is_signaling_nan(farg1.d) ||
+                     float64_is_signaling_nan(farg2.d)))) {
+        /* sNaN comparison */
+        fload_invalid_op_excp(POWERPC_EXCP_FP_VXSNAN);
+    }
 }
 
-uint32_t helper_fcmpo (uint64_t arg1, uint64_t arg2)
+void helper_fcmpo (uint64_t arg1, uint64_t arg2, uint32_t crfD)
 {
     CPU_DoubleU farg1, farg2;
     uint32_t ret = 0;
@@ -1654,6 +1658,19 @@
 
     if (unlikely(float64_is_nan(farg1.d) ||
                  float64_is_nan(farg2.d))) {
+        ret = 0x01UL;
+    } else if (float64_lt(farg1.d, farg2.d, &env->fp_status)) {
+        ret = 0x08UL;
+    } else if (!float64_le(farg1.d, farg2.d, &env->fp_status)) {
+        ret = 0x04UL;
+    } else {
+        ret = 0x02UL;
+    }
+
+    env->fpscr &= ~(0x0F << FPSCR_FPRF);
+    env->fpscr |= ret << FPSCR_FPRF;
+    env->crf[crfD] = ret;
+    if (unlikely (ret == 0x01UL)) {
         if (float64_is_signaling_nan(farg1.d) ||
             float64_is_signaling_nan(farg2.d)) {
             /* sNaN comparison */
@@ -1663,18 +1680,7 @@
             /* qNaN comparison */
             fload_invalid_op_excp(POWERPC_EXCP_FP_VXVC);
         }
-    } else {
-        if (float64_lt(farg1.d, farg2.d, &env->fp_status)) {
-            ret = 0x08UL;
-        } else if (!float64_le(farg1.d, farg2.d, &env->fp_status)) {
-            ret = 0x04UL;
-        } else {
-            ret = 0x02UL;
-        }
     }
-    env->fpscr &= ~(0x0F << FPSCR_FPRF);
-    env->fpscr |= ret << FPSCR_FPRF;
-    return ret;
 }
 
 #if !defined (CONFIG_USER_ONLY)

Modified: trunk/target-ppc/translate.c
===================================================================
--- trunk/target-ppc/translate.c        2008-12-14 18:59:08 UTC (rev 6033)
+++ trunk/target-ppc/translate.c        2008-12-14 19:34:09 UTC (rev 6034)
@@ -2249,26 +2249,30 @@
 /* fcmpo */
 GEN_HANDLER(fcmpo, 0x3F, 0x00, 0x01, 0x00600001, PPC_FLOAT)
 {
+    TCGv crf;
     if (unlikely(!ctx->fpu_enabled)) {
         gen_exception(ctx, POWERPC_EXCP_FPU);
         return;
     }
     gen_reset_fpstatus();
-    gen_helper_fcmpo(cpu_crf[crfD(ctx->opcode)],
-                     cpu_fpr[rA(ctx->opcode)], cpu_fpr[rB(ctx->opcode)]);
+    crf = tcg_const_i32(crfD(ctx->opcode));
+    gen_helper_fcmpo(cpu_fpr[rA(ctx->opcode)], cpu_fpr[rB(ctx->opcode)], crf);
+    tcg_temp_free(crf);
     gen_helper_float_check_status();
 }
 
 /* fcmpu */
 GEN_HANDLER(fcmpu, 0x3F, 0x00, 0x00, 0x00600001, PPC_FLOAT)
 {
+    TCGv crf;
     if (unlikely(!ctx->fpu_enabled)) {
         gen_exception(ctx, POWERPC_EXCP_FPU);
         return;
     }
     gen_reset_fpstatus();
-    gen_helper_fcmpu(cpu_crf[crfD(ctx->opcode)],
-                     cpu_fpr[rA(ctx->opcode)], cpu_fpr[rB(ctx->opcode)]);
+    crf = tcg_const_i32(crfD(ctx->opcode));
+    gen_helper_fcmpu(cpu_fpr[rA(ctx->opcode)], cpu_fpr[rB(ctx->opcode)], crf);
+    tcg_temp_free(crf);
     gen_helper_float_check_status();
 }