diff mbox series

[08/33] target/ppc: Implement cnttzdm

Message ID 20211021194547.672988-9-matheus.ferst@eldorado.org.br
State Superseded
Headers show
Series PowerISA v3.1 instruction batch | expand

Commit Message

Matheus K. Ferst Oct. 21, 2021, 7:45 p.m. UTC 
From: Luis Pires <luis.pires@eldorado.org.br>

Implement the following PowerISA v3.1 instruction:
cnttzdm: Count Trailing Zeros Doubleword Under Bit Mask

Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
---
 target/ppc/helper.h                        |  1 +
 target/ppc/insn32.decode                   |  1 +
 target/ppc/int_helper.c                    | 16 ++++++++++++++++
 target/ppc/translate/fixedpoint-impl.c.inc | 12 ++++++++++++
 4 files changed, 30 insertions(+)

Comments

Richard Henderson Oct. 22, 2021, 11:55 p.m. UTC | #1 
On 10/21/21 12:45 PM, matheus.ferst@eldorado.org.br wrote:
> +uint64_t helper_CNTTZDM(uint64_t src, uint64_t mask)
> +{
> +    uint64_t count = 0;
> +
> +    while (mask != 0) {
> +        if ((src >> ctz64(mask)) & 1) {
> +            break;
> +        }
> +
> +        count++;
> +        mask &= mask - 1;
> +    }
> +
> +    return count;
> +}

Similar to cntlzdm, we can use src & mask.

r~
diff mbox series

Patch

diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index ee7c82fb60..115bdf474a 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -48,6 +48,7 @@  DEF_HELPER_FLAGS_2(cmpb, TCG_CALL_NO_RWG_SE, tl, tl, tl)
 DEF_HELPER_3(sraw, tl, env, tl, tl)
 DEF_HELPER_FLAGS_2(cfuged, TCG_CALL_NO_RWG_SE, i64, i64, i64)
 DEF_HELPER_FLAGS_2(CNTLZDM, TCG_CALL_NO_RWG_SE, i64, i64, i64)
+DEF_HELPER_FLAGS_2(CNTTZDM, TCG_CALL_NO_RWG_SE, i64, i64, i64)
 #if defined(TARGET_PPC64)
 DEF_HELPER_FLAGS_2(cmpeqb, TCG_CALL_NO_RWG_SE, i32, tl, tl)
 DEF_HELPER_FLAGS_1(popcntw, TCG_CALL_NO_RWG_SE, tl, tl)
diff --git a/target/ppc/insn32.decode b/target/ppc/insn32.decode
index 221cb00dd6..3d692e9e6a 100644
--- a/target/ppc/insn32.decode
+++ b/target/ppc/insn32.decode
@@ -204,6 +204,7 @@  ADDPCIS         010011 ..... ..... .......... 00010 .   @DX
 
 CFUGED          011111 ..... ..... ..... 0011011100 -   @X
 CNTLZDM         011111 ..... ..... ..... 0000111011 -   @X
+CNTTZDM         011111 ..... ..... ..... 1000111011 -   @X
 
 ### Float-Point Load Instructions
 
diff --git a/target/ppc/int_helper.c b/target/ppc/int_helper.c
index dcef356034..efda78ed8e 100644
--- a/target/ppc/int_helper.c
+++ b/target/ppc/int_helper.c
@@ -404,6 +404,22 @@  uint64_t helper_CNTLZDM(uint64_t src, uint64_t mask)
     return count;
 }
 
+uint64_t helper_CNTTZDM(uint64_t src, uint64_t mask)
+{
+    uint64_t count = 0;
+
+    while (mask != 0) {
+        if ((src >> ctz64(mask)) & 1) {
+            break;
+        }
+
+        count++;
+        mask &= mask - 1;
+    }
+
+    return count;
+}
+
 /*****************************************************************************/
 /* PowerPC 601 specific instructions (POWER bridge) */
 target_ulong helper_div(CPUPPCState *env, target_ulong arg1, target_ulong arg2)
diff --git a/target/ppc/translate/fixedpoint-impl.c.inc b/target/ppc/translate/fixedpoint-impl.c.inc
index 814fef2782..8c66fca96a 100644
--- a/target/ppc/translate/fixedpoint-impl.c.inc
+++ b/target/ppc/translate/fixedpoint-impl.c.inc
@@ -427,3 +427,15 @@  static bool trans_CNTLZDM(DisasContext *ctx, arg_X *a)
 #endif
     return true;
 }
+
+static bool trans_CNTTZDM(DisasContext *ctx, arg_X *a)
+{
+    REQUIRE_64BIT(ctx);
+    REQUIRE_INSNS_FLAGS2(ctx, ISA310);
+#if defined(TARGET_PPC64)
+    gen_helper_CNTTZDM(cpu_gpr[a->ra], cpu_gpr[a->rt], cpu_gpr[a->rb]);
+#else
+    qemu_build_not_reached();
+#endif
+    return true;
+}