target/ppc: introduce set_dfp{64,128}() helper functions

The existing functions (now incorrectly) assume that the MSB and LSB of DFP
numbers are stored as consecutive 64-bit words in memory. Instead of accessing
the DFP numbers directly, introduce set_dfp{64,128}() helper functions to ease
the switch to the correct representation.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20190926185801.11176-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 48 insertions, 42 deletions

diff --git a/target/ppc/dfp_helper.c b/target/ppc/dfp_helper.c
index e4369ebe9b..3923a072b2 100644
--- a/target/ppc/dfp_helper.c
+++ b/target/ppc/dfp_helper.c
@@ -47,6 +47,17 @@ static void get_dfp128(uint64_t *dst, uint64_t *dfp)
     dst[1] = dfp[LO_IDX];
 }
 
+static void set_dfp64(uint64_t *dfp, uint64_t *src)
+{
+    dfp[0] = src[0];
+}
+
+static void set_dfp128(uint64_t *dfp, uint64_t *src)
+{
+    dfp[0] = src[HI_IDX];
+    dfp[1] = src[LO_IDX];
+}
+
 struct PPC_DFP {
     CPUPPCState *env;
     uint64_t t64[2], a64[2], b64[2];
@@ -413,10 +424,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b)      \
     decimal##size##FromNumber((decimal##size *)dfp.t64, &dfp.t, &dfp.context); \
     postprocs(&dfp);                                                           \
     if (size == 64) {                                                          \
-        t[0] = dfp.t64[0];                                                     \
+        set_dfp64(t, dfp.t64);                                                 \
     } else if (size == 128) {                                                  \
-        t[0] = dfp.t64[HI_IDX];                                                \
-        t[1] = dfp.t64[LO_IDX];                                                \
+        set_dfp128(t, dfp.t64);                                                \
     }                                                                          \
 }
 
@@ -735,10 +745,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b,            \
     QUA_PPs(&dfp);                                                      \
                                                                         \
     if (size == 64) {                                                   \
-        t[0] = dfp.t64[0];                                              \
+        set_dfp64(t, dfp.t64);                                          \
     } else if (size == 128) {                                           \
-        t[0] = dfp.t64[HI_IDX];                                         \
-        t[1] = dfp.t64[LO_IDX];                                         \
+        set_dfp128(t, dfp.t64);                                         \
     }                                                                   \
 }
 
@@ -759,10 +768,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,            \
     QUA_PPs(&dfp);                                                      \
                                                                         \
     if (size == 64) {                                                   \
-        t[0] = dfp.t64[0];                                              \
+        set_dfp64(t, dfp.t64);                                          \
     } else if (size == 128) {                                           \
-        t[0] = dfp.t64[HI_IDX];                                         \
-        t[1] = dfp.t64[LO_IDX];                                         \
+        set_dfp128(t, dfp.t64);                                         \
     }                                                                   \
 }
 
@@ -843,10 +851,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,            \
     QUA_PPs(&dfp);                                                      \
                                                                         \
     if (size == 64) {                                                   \
-        t[0] = dfp.t64[0];                                              \
+        set_dfp64(t, dfp.t64);                                          \
     } else if (size == 128) {                                           \
-        t[0] = dfp.t64[HI_IDX];                                         \
-        t[1] = dfp.t64[LO_IDX];                                         \
+        set_dfp128(t, dfp.t64);                                         \
     }                                                                   \
 }
 
@@ -867,10 +874,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b,                   \
     postprocs(&dfp);                                                           \
                                                                                \
     if (size == 64) {                                                          \
-        t[0] = dfp.t64[0];                                                     \
+        set_dfp64(t, dfp.t64);                                                 \
     } else if (size == 128) {                                                  \
-        t[0] = dfp.t64[HI_IDX];                                                \
-        t[1] = dfp.t64[LO_IDX];                                                \
+        set_dfp128(t, dfp.t64);                                                \
     }                                                                          \
 }
 
@@ -904,7 +910,8 @@ void helper_dctdp(CPUPPCState *env, uint64_t *t, uint64_t *b)
 
     dfp_prepare_decimal64(&dfp, 0, 0, env);
     decimal32ToNumber((decimal32 *)&b_short, &dfp.t);
-    decimal64FromNumber((decimal64 *)t, &dfp.t, &dfp.context);
+    decimal64FromNumber((decimal64 *)&dfp.t64, &dfp.t, &dfp.context);
+    set_dfp64(t, dfp.t64);
     dfp_set_FPRF_from_FRT(&dfp);
 }
 
@@ -920,14 +927,14 @@ void helper_dctqpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
     dfp_set_FPRF_from_FRT(&dfp);
 
     decimal128FromNumber((decimal128 *)&dfp.t64, &dfp.t, &dfp.context);
-    t[0] = dfp.t64[HI_IDX];
-    t[1] = dfp.t64[LO_IDX];
+    set_dfp128(t, dfp.t64);
 }
 
 void helper_drsp(CPUPPCState *env, uint64_t *t, uint64_t *b)
 {
     struct PPC_DFP dfp;
     uint32_t t_short = 0;
+    uint64_t t64;
     dfp_prepare_decimal64(&dfp, 0, b, env);
     decimal32FromNumber((decimal32 *)&t_short, &dfp.b, &dfp.context);
     decimal32ToNumber((decimal32 *)&t_short, &dfp.t);
@@ -937,7 +944,8 @@ void helper_drsp(CPUPPCState *env, uint64_t *t, uint64_t *b)
     dfp_check_for_UX(&dfp);
     dfp_check_for_XX(&dfp);
 
-    *t = t_short;
+    t64 = (uint64_t)t_short;
+    set_dfp64(t, &t64);
 }
 
 void helper_drdpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
@@ -953,9 +961,9 @@ void helper_drdpq(CPUPPCState *env, uint64_t *t, uint64_t *b)
     dfp_check_for_UX(&dfp);
     dfp_check_for_XX(&dfp);
 
+    dfp.t64[0] = dfp.t64[1] = 0;
     decimal64FromNumber((decimal64 *)dfp.t64, &dfp.t, &dfp.context);
-    t[0] = dfp.t64[0];
-    t[1] = 0;
+    set_dfp128(t, dfp.t64);
 }
 
 #define DFP_HELPER_CFFIX(op, size)                                             \
@@ -970,10 +978,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)                   \
     CFFIX_PPs(&dfp);                                                           \
                                                                                \
     if (size == 64) {                                                          \
-        t[0] = dfp.t64[0];                                                     \
+        set_dfp64(t, dfp.t64);                                                 \
     } else if (size == 128) {                                                  \
-        t[0] = dfp.t64[HI_IDX];                                                \
-        t[1] = dfp.t64[LO_IDX];                                                \
+        set_dfp128(t, dfp.t64);                                                \
     }                                                                          \
 }
 
@@ -1016,7 +1023,7 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)                  \
         }                                                                     \
     }                                                                         \
                                                                               \
-    *t = dfp.t64[0];                                                          \
+    set_dfp64(t, dfp.t64);                                                    \
 }
 
 DFP_HELPER_CTFIX(dctfix, 64)
@@ -1078,10 +1085,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t sp) \
     }                                                                     \
                                                                           \
     if (size == 64) {                                                     \
-        t[0] = dfp.t64[0];                                                \
+        set_dfp64(t, dfp.t64);                                            \
     } else if (size == 128) {                                             \
-        t[0] = dfp.t64[HI_IDX];                                           \
-        t[1] = dfp.t64[LO_IDX];                                           \
+        set_dfp128(t, dfp.t64);                                           \
     }                                                                     \
 }
 
@@ -1150,10 +1156,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b, uint32_t s)     \
                               &dfp.context);                                 \
     dfp_set_FPRF_from_FRT(&dfp);                                             \
     if ((size) == 64) {                                                      \
-        t[0] = dfp.t64[0];                                                   \
+        set_dfp64(t, dfp.t64);                                               \
     } else if ((size) == 128) {                                              \
-        t[0] = dfp.t64[HI_IDX];                                              \
-        t[1] = dfp.t64[LO_IDX];                                              \
+        set_dfp128(t, dfp.t64);                                              \
     }                                                                        \
 }
 
@@ -1164,27 +1169,30 @@ DFP_HELPER_ENBCD(denbcdq, 128)
 void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *b)   \
 {                                                              \
     struct PPC_DFP dfp;                                        \
+    uint64_t t64;                                              \
                                                                \
     dfp_prepare_decimal##size(&dfp, 0, b, env);                \
                                                                \
     if (unlikely(decNumberIsSpecial(&dfp.b))) {                \
         if (decNumberIsInfinite(&dfp.b)) {                     \
-            *t = -1;                                           \
+            t64 = -1;                                          \
         } else if (decNumberIsSNaN(&dfp.b)) {                  \
-            *t = -3;                                           \
+            t64 = -3;                                          \
         } else if (decNumberIsQNaN(&dfp.b)) {                  \
-            *t = -2;                                           \
+            t64 = -2;                                          \
         } else {                                               \
             assert(0);                                         \
         }                                                      \
+        set_dfp64(t, &t64);                                    \
     } else {                                                   \
         if ((size) == 64) {                                    \
-            *t = dfp.b.exponent + 398;                         \
+            t64 = dfp.b.exponent + 398;                        \
         } else if ((size) == 128) {                            \
-            *t = dfp.b.exponent + 6176;                        \
+            t64 = dfp.b.exponent + 6176;                       \
         } else {                                               \
             assert(0);                                         \
         }                                                      \
+        set_dfp64(t, &t64);                                    \
     }                                                          \
 }
 
@@ -1251,10 +1259,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a, uint64_t *b) \
                                   &dfp.context);                          \
     }                                                                     \
     if (size == 64) {                                                     \
-        t[0] = dfp.t64[0];                                                \
+        set_dfp64(t, dfp.t64);                                            \
     } else if (size == 128) {                                             \
-        t[0] = dfp.t64[HI_IDX];                                           \
-        t[1] = dfp.t64[LO_IDX];                                           \
+        set_dfp128(t, dfp.t64);                                           \
     }                                                                     \
 }
 
@@ -1344,10 +1351,9 @@ void helper_##op(CPUPPCState *env, uint64_t *t, uint64_t *a,        \
     }                                                               \
                                                                     \
     if ((size) == 64) {                                             \
-        t[0] = dfp.t64[0];                                          \
+        set_dfp64(t, dfp.t64);                                      \
     } else {                                                        \
-        t[0] = dfp.t64[HI_IDX];                                     \
-        t[1] = dfp.t64[LO_IDX];                                     \
+        set_dfp128(t, dfp.t64);                                     \
     }                                                               \
 }