[PATCH 07/33] target/ppc: Implement cntlzdm

From: matheus.ferst@eldorado.org.br
To: qemu-devel@nongnu.org, qemu-ppc@nongnu.org
Cc: lucas.castro@eldorado.org.br, richard.henderson@linaro.org,
	groug@kaod.org, luis.pires@eldorado.org.br,
	matheus.ferst@eldorado.org.br, david@gibson.dropbear.id.au
Subject: [PATCH 07/33] target/ppc: Implement cntlzdm
Date: Thu, 21 Oct 2021 16:45:21 -0300	[thread overview]
Message-ID: <20211021194547.672988-8-matheus.ferst@eldorado.org.br> (raw)
In-Reply-To: <20211021194547.672988-1-matheus.ferst@eldorado.org.br>

From: Luis Pires <luis.pires@eldorado.org.br>

Implement the following PowerISA v3.1 instruction:
cntlzdm: Count Leading 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                    | 18 ++++++++++++++++++
 target/ppc/translate/fixedpoint-impl.c.inc | 12 ++++++++++++
 4 files changed, 32 insertions(+)

diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 6fa3e15fe9..ee7c82fb60 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -47,6 +47,7 @@ DEF_HELPER_FLAGS_1(popcntb, TCG_CALL_NO_RWG_SE, tl, tl)
 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)
 #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 9cb9fc00b8..221cb00dd6 100644
--- a/target/ppc/insn32.decode
+++ b/target/ppc/insn32.decode
@@ -203,6 +203,7 @@ 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/int_helper.c b/target/ppc/int_helper.c
index b3d302390a..dcef356034 100644
--- a/target/ppc/int_helper.c
+++ b/target/ppc/int_helper.c
@@ -386,6 +386,24 @@ uint64_t helper_cfuged(uint64_t src, uint64_t mask)
     return left | (right >> n);
 }
 
+uint64_t helper_CNTLZDM(uint64_t src, uint64_t mask)
+{
+    uint64_t sel_bit, count = 0;
+
+    while (mask != 0) {
+        sel_bit = 0x8000000000000000ULL >> clz64(mask);
+
+        if (src & sel_bit) {
+            break;
+        }
+
+        count++;
+        mask &= ~sel_bit;
+    }
+
+    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 0a6b3d61d1..814fef2782 100644
--- a/target/ppc/translate/fixedpoint-impl.c.inc
+++ b/target/ppc/translate/fixedpoint-impl.c.inc
@@ -415,3 +415,15 @@ static bool trans_CFUGED(DisasContext *ctx, arg_X *a)
 #endif
     return true;
 }
+
+static bool trans_CNTLZDM(DisasContext *ctx, arg_X *a)
+{
+    REQUIRE_64BIT(ctx);
+    REQUIRE_INSNS_FLAGS2(ctx, ISA310);
+#if defined(TARGET_PPC64)
+    gen_helper_CNTLZDM(cpu_gpr[a->ra], cpu_gpr[a->rt], cpu_gpr[a->rb]);
+#else
+    qemu_build_not_reached();
+#endif
+    return true;
+}
-- 
2.25.1


