ppc: Add support for 'mffsce' instruction

ISA 3.0B added a set of Floating-Point Status and Control Register (FPSCR)
instructions: mffsce, mffscdrn, mffscdrni, mffscrn, mffscrni, mffsl.
This patch adds support for 'mffsce' instruction.

'mffsce' is identical to 'mffs', except that it also clears the exception
enable bits in the FPSCR.

On CPUs without support for 'mffsce' (below ISA 3.0), the
instruction will execute identically to 'mffs'.

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <1568817082-1384-1-git-send-email-pc@us.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/target/ppc/translate/fp-impl.inc.c b/target/ppc/translate/fp-impl.inc.c
index 75f9523b0748f9467a585b9e1565ed604f26ac19..d8e27bf4d521677a371db9ac90bd80073c2b7209 100644 (file)
--- a/target/ppc/translate/fp-impl.inc.c
+++ b/target/ppc/translate/fp-impl.inc.c
@@ -639,6 +639,36 @@ static void gen_mffsl(DisasContext *ctx)
     tcg_temp_free_i64(t0);
 }
 
+/* mffsce */
+static void gen_mffsce(DisasContext *ctx)
+{
+    TCGv_i64 t0;
+    TCGv_i32 mask;
+
+    if (unlikely(!(ctx->insns_flags2 & PPC2_ISA300))) {
+        return gen_mffs(ctx);
+    }
+
+    if (unlikely(!ctx->fpu_enabled)) {
+        gen_exception(ctx, POWERPC_EXCP_FPU);
+        return;
+    }
+
+    t0 = tcg_temp_new_i64();
+
+    gen_reset_fpstatus();
+    tcg_gen_extu_tl_i64(t0, cpu_fpscr);
+    set_fpr(rD(ctx->opcode), t0);
+
+    /* Clear exception enable bits in the FPSCR.  */
+    tcg_gen_andi_i64(t0, t0, ~FP_ENABLES);
+    mask = tcg_const_i32(0x0003);
+    gen_helper_store_fpscr(cpu_env, t0, mask);
+
+    tcg_temp_free_i32(mask);
+    tcg_temp_free_i64(t0);
+}
+
 static void gen_helper_mffscrn(DisasContext *ctx, TCGv_i64 t1)
 {
     TCGv_i64 t0 = tcg_temp_new_i64();

diff --git a/target/ppc/translate/fp-ops.inc.c b/target/ppc/translate/fp-ops.inc.c
index f2bcf0e67bb6a037961cf480e24abfe35cf68ae1..88fab6562815b656ff78baab4062020b5d4ae2e1 100644 (file)
--- a/target/ppc/translate/fp-ops.inc.c
+++ b/target/ppc/translate/fp-ops.inc.c
@@ -105,6 +105,8 @@ GEN_HANDLER_E(fmrgew, 0x3F, 0x06, 0x1E, 0x00000001, PPC_NONE, PPC2_VSX207),
 GEN_HANDLER_E(fmrgow, 0x3F, 0x06, 0x1A, 0x00000001, PPC_NONE, PPC2_VSX207),
 GEN_HANDLER(mcrfs, 0x3F, 0x00, 0x02, 0x0063F801, PPC_FLOAT),
 GEN_HANDLER_E_2(mffs, 0x3F, 0x07, 0x12, 0x00, 0x00000000, PPC_FLOAT, PPC_NONE),
+GEN_HANDLER_E_2(mffsce, 0x3F, 0x07, 0x12, 0x01, 0x00000000, PPC_FLOAT,
+    PPC2_ISA300),
 GEN_HANDLER_E_2(mffsl, 0x3F, 0x07, 0x12, 0x18, 0x00000000, PPC_FLOAT,
     PPC2_ISA300),
 GEN_HANDLER_E_2(mffscrn, 0x3F, 0x07, 0x12, 0x16, 0x00000000, PPC_FLOAT,