[PATCH 1/1] target-ppc: fix rlwimi, rlwinm, rlwnm for Clang-9

[Daniele Buono]

Starting with Clang v9, -Wtype-limits is implemented and triggers a
few "result of comparison is always true" errors when compiling PPC32
targets.

The comparisons seem to be necessary only on PPC64, since the
else branch in PPC32 only has a "g_assert_not_reached();" in all cases.

This patch restructures the code so that PPC32 does not execute the
check, while PPC64 works like before

Signed-off-by: Daniele Buono <dbu...@linux.vnet.ibm.com>
---
 target/ppc/translate.c | 34 +++++++++++++++++++---------------
 1 file changed, 19 insertions(+), 15 deletions(-)

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 807d14faaa..9400fa2c7c 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -1882,6 +1882,7 @@ static void gen_rlwimi(DisasContext *ctx)
         tcg_gen_deposit_tl(t_ra, t_ra, t_rs, sh, me - mb + 1);
     } else {
         target_ulong mask;
+        TCGv_i32 t0;
         TCGv t1;
 
 #if defined(TARGET_PPC64)
@@ -1891,20 +1892,20 @@ static void gen_rlwimi(DisasContext *ctx)
         mask = MASK(mb, me);
 
         t1 = tcg_temp_new();
+#if defined(TARGET_PPC64)
         if (mask <= 0xffffffffu) {
-            TCGv_i32 t0 = tcg_temp_new_i32();
+#endif
+            t0 = tcg_temp_new_i32();
             tcg_gen_trunc_tl_i32(t0, t_rs);
             tcg_gen_rotli_i32(t0, t0, sh);
             tcg_gen_extu_i32_tl(t1, t0);
             tcg_temp_free_i32(t0);
-        } else {
 #if defined(TARGET_PPC64)
+        } else {
             tcg_gen_deposit_i64(t1, t_rs, t_rs, 32, 32);
             tcg_gen_rotli_i64(t1, t1, sh);
-#else
-            g_assert_not_reached();
-#endif
         }
+#endif
 
         tcg_gen_andi_tl(t1, t1, mask);
         tcg_gen_andi_tl(t_ra, t_ra, ~mask);
@@ -1938,7 +1939,9 @@ static void gen_rlwinm(DisasContext *ctx)
         me += 32;
 #endif
         mask = MASK(mb, me);
+#if defined(TARGET_PPC64)
         if (mask <= 0xffffffffu) {
+#endif
             if (sh == 0) {
                 tcg_gen_andi_tl(t_ra, t_rs, mask);
             } else {
@@ -1949,15 +1952,13 @@ static void gen_rlwinm(DisasContext *ctx)
                 tcg_gen_extu_i32_tl(t_ra, t0);
                 tcg_temp_free_i32(t0);
             }
-        } else {
 #if defined(TARGET_PPC64)
+        } else {
             tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32);
             tcg_gen_rotli_i64(t_ra, t_ra, sh);
             tcg_gen_andi_i64(t_ra, t_ra, mask);
-#else
-            g_assert_not_reached();
-#endif
         }
+#endif
     }
     if (unlikely(Rc(ctx->opcode) != 0)) {
         gen_set_Rc0(ctx, t_ra);
@@ -1972,6 +1973,9 @@ static void gen_rlwnm(DisasContext *ctx)
     TCGv t_rb = cpu_gpr[rB(ctx->opcode)];
     uint32_t mb = MB(ctx->opcode);
     uint32_t me = ME(ctx->opcode);
+    TCGv_i32 t0;
+    TCGv_i32 t1;
+
     target_ulong mask;
 
 #if defined(TARGET_PPC64)
@@ -1980,9 +1984,11 @@ static void gen_rlwnm(DisasContext *ctx)
 #endif
     mask = MASK(mb, me);
 
+#if defined(TARGET_PPC64)
     if (mask <= 0xffffffffu) {
-        TCGv_i32 t0 = tcg_temp_new_i32();
-        TCGv_i32 t1 = tcg_temp_new_i32();
+#endif
+        t0 = tcg_temp_new_i32();
+        t1 = tcg_temp_new_i32();
         tcg_gen_trunc_tl_i32(t0, t_rb);
         tcg_gen_trunc_tl_i32(t1, t_rs);
         tcg_gen_andi_i32(t0, t0, 0x1f);
@@ -1990,17 +1996,15 @@ static void gen_rlwnm(DisasContext *ctx)
         tcg_gen_extu_i32_tl(t_ra, t1);
         tcg_temp_free_i32(t0);
         tcg_temp_free_i32(t1);
-    } else {
 #if defined(TARGET_PPC64)
+    } else {
         TCGv_i64 t0 = tcg_temp_new_i64();
         tcg_gen_andi_i64(t0, t_rb, 0x1f);
         tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32);
         tcg_gen_rotl_i64(t_ra, t_ra, t0);
         tcg_temp_free_i64(t0);
-#else
-        g_assert_not_reached();
-#endif
     }
+#endif
 
     tcg_gen_andi_tl(t_ra, t_ra, mask);
 
-- 
2.26.2