target/ppc: Implement cntlzdm

Implement the following PowerISA v3.1 instruction:
cntlzdm: Count Leading Zeros Doubleword Under Bit Mask

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20211029202424.175401-8-matheus.ferst@eldorado.org.br>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/target/ppc/insn32.decode b/target/ppc/insn32.decode
index 7ff8c25ac50f9c63fe8ec3cf1ec1fde21db04caa..eb3383c99c60d115656e20c832e1fcc3b8fd44df 100644 (file)
--- a/target/ppc/insn32.decode
+++ b/target/ppc/insn32.decode
@@ -124,6 +124,7 @@ ADDPCIS         010011 ..... ..... .......... 00010 .   @DX
 ## Fixed-Point Logical Instructions
 
 CFUGED          011111 ..... ..... ..... 0011011100 -   @X
+CNTLZDM         011111 ..... ..... ..... 0000111011 -   @X
 
 ### Float-Point Load Instructions
 

diff --git a/target/ppc/translate/fixedpoint-impl.c.inc b/target/ppc/translate/fixedpoint-impl.c.inc
index 0d9c6e0996fc01607e8eb95c8abd2ac97d222bc5..c9e9ae35df4855c25a2b0596cb02e6efc566e0e1 100644 (file)
--- a/target/ppc/translate/fixedpoint-impl.c.inc
+++ b/target/ppc/translate/fixedpoint-impl.c.inc
@@ -413,3 +413,39 @@ static bool trans_CFUGED(DisasContext *ctx, arg_X *a)
 #endif
     return true;
 }
+
+#if defined(TARGET_PPC64)
+static void do_cntlzdm(TCGv_i64 dst, TCGv_i64 src, TCGv_i64 mask)
+{
+    TCGv_i64 tmp;
+    TCGLabel *l1;
+
+    tmp = tcg_temp_local_new_i64();
+    l1 = gen_new_label();
+
+    tcg_gen_and_i64(tmp, src, mask);
+    tcg_gen_clzi_i64(tmp, tmp, 64);
+
+    tcg_gen_brcondi_i64(TCG_COND_EQ, tmp, 0, l1);
+
+    tcg_gen_subfi_i64(tmp, 64, tmp);
+    tcg_gen_shr_i64(tmp, mask, tmp);
+    tcg_gen_ctpop_i64(tmp, tmp);
+
+    gen_set_label(l1);
+
+    tcg_gen_mov_i64(dst, tmp);
+}
+#endif
+
+static bool trans_CNTLZDM(DisasContext *ctx, arg_X *a)
+{
+    REQUIRE_64BIT(ctx);
+    REQUIRE_INSNS_FLAGS2(ctx, ISA310);
+#if defined(TARGET_PPC64)
+    do_cntlzdm(cpu_gpr[a->ra], cpu_gpr[a->rt], cpu_gpr[a->rb]);
+#else
+    qemu_build_not_reached();
+#endif
+    return true;
+}