[Qemu-devel] [PATCH v3] target/ppc: Fix carry flag setting for shift algebraic instructions

[Sandipan Das <sandipan@linux.vnet.ibm.com>]

For POWER ISA v3.0, the XER bit CA32 needs to be set by the shift
right algebraic instructions whenever the CA bit is to be set. This
change affects the following instructions:
  * Shift Right Algebraic Word (sraw[.])
  * Shift Right Algebraic Word Immediate (srawi[.])
  * Shift Right Algebraic Doubleword (srad[.])
  * Shift Right Algebraic Doubleword Immediate (sradi[.])

Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
---
v2: Add tcg_temp_free() required in gen_sraw() and gen_srad()

v3: Remove explicit checking for ISA v3.0 when setting CA32
---
 target/ppc/int_helper.c | 8 ++++++++
 target/ppc/translate.c  | 8 ++++++++
 2 files changed, 16 insertions(+)

diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c
index da4e1a62c9..0bdd96aebe 100644
--- a/target/ppc/int_helper.c
+++ b/target/ppc/int_helper.c
@@ -231,6 +231,10 @@ target_ulong helper_sraw(CPUPPCState *env, target_ulong value,
         ret = (int32_t)value >> 31;
         env->ca = (ret != 0);
     }
+
+    /* update CA32 for ISA v3.0 */
+    env->ca32 = env->ca;
+
     return (target_long)ret;
 }
 
@@ -257,6 +261,10 @@ target_ulong helper_srad(CPUPPCState *env, target_ulong value,
         ret = (int64_t)value >> 63;
         env->ca = (ret != 0);
     }
+
+    /* update CA32 for ISA v3.0 */
+    env->ca32 = env->ca;
+
     return ret;
 }
 #endif
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 606b605ba0..c35a2027eb 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -2192,6 +2192,10 @@ static void gen_srawi(DisasContext *ctx)
         tcg_gen_setcondi_tl(TCG_COND_NE, cpu_ca, cpu_ca, 0);
         tcg_gen_sari_tl(dst, dst, sh);
     }
+
+    /* update CA32 for ISA v3.0 */
+    tcg_gen_mov_tl(cpu_ca32, cpu_ca);
+
     if (unlikely(Rc(ctx->opcode) != 0)) {
         gen_set_Rc0(ctx, dst);
     }
@@ -2269,6 +2273,10 @@ static inline void gen_sradi(DisasContext *ctx, int n)
         tcg_gen_setcondi_tl(TCG_COND_NE, cpu_ca, cpu_ca, 0);
         tcg_gen_sari_tl(dst, src, sh);
     }
+
+    /* update CA32 for ISA v3.0 */
+    tcg_gen_mov_tl(cpu_ca32, cpu_ca);
+
     if (unlikely(Rc(ctx->opcode) != 0)) {
         gen_set_Rc0(ctx, dst);
     }
-- 
2.13.5