From: Egor Bogatov <egorbo@gmail.com>
Date: Mon, 26 Aug 2019 18:08:53 +0000 (+0300)
Subject: Implement Lzcnt hw intrinsics
X-Git-Tag: submit/tizen/20210909.063632~10331^2~5^2~687^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7635724e437530421bfd4bf71566b9406dca3d64;p=platform%2Fupstream%2Fdotnet%2Fruntime.git

Implement Lzcnt hw intrinsics


Commit migrated from https://github.com/mono/mono/commit/044d1519bdf40f37ec06128dd383c21157dc3c0e
---

diff --git a/src/mono/mono/mini/llvm-jit.cpp b/src/mono/mono/mini/llvm-jit.cpp
index 8ea0050..4672962 100644
--- a/src/mono/mono/mini/llvm-jit.cpp
+++ b/src/mono/mono/mini/llvm-jit.cpp
@@ -465,6 +465,8 @@ mono_llvm_get_cpu_features (void)
 		if (llvm::sys::getHostCPUFeatures(HostFeatures)) {
 			if (HostFeatures ["popcnt"])
 				f |= MONO_CPU_X86_POPCNT;
+			if (HostFeatures ["lzcnt"])
+				f |= MONO_CPU_X86_LZCNT;
 			if (HostFeatures ["avx"])
 				f |= MONO_CPU_X86_AVX;
 			if (HostFeatures ["bmi"])
diff --git a/src/mono/mono/mini/mini-llvm.c b/src/mono/mono/mini/mini-llvm.c
index cdbb13a..b672119 100644
--- a/src/mono/mono/mini/mini-llvm.c
+++ b/src/mono/mono/mini/mini-llvm.c
@@ -303,6 +303,8 @@ typedef enum {
 	INTRINS_EXPECT_I1,
 	INTRINS_CTPOP_I32,
 	INTRINS_CTPOP_I64,
+	INTRINS_CTLZ_I32,
+	INTRINS_CTLZ_I64,
 	INTRINS_CTTZ_I32,
 	INTRINS_CTTZ_I64,
 	INTRINS_PEXT_I32,
@@ -7216,6 +7218,12 @@ process_bb (EmitContext *ctx, MonoBasicBlock *bb)
 		case OP_POPCNT64:
 			values [ins->dreg] = LLVMBuildCall (builder, get_intrins (ctx, INTRINS_CTPOP_I64), &lhs, 1, "");
 			break;
+		case OP_LZCNT32:
+			values [ins->dreg] = LLVMBuildCall (builder, get_intrins (ctx, INTRINS_CTLZ_I32), &lhs, 1, "");
+			break;
+		case OP_LZCNT64:
+			values [ins->dreg] = LLVMBuildCall (builder, get_intrins (ctx, INTRINS_CTLZ_I64), &lhs, 1, "");
+			break;
 		case OP_CTTZ32:
 		case OP_CTTZ64: {
 			LLVMValueRef args [2];
@@ -8462,6 +8470,8 @@ static IntrinsicDesc intrinsics[] = {
 	{INTRINS_EXPECT_I1, "llvm.expect.i1"},
 	{INTRINS_CTPOP_I32, "llvm.ctpop.i32"},
 	{INTRINS_CTPOP_I64, "llvm.ctpop.i64"},
+	{INTRINS_CTLZ_I32, "llvm.ctlz.i32"},
+	{INTRINS_CTLZ_I64, "llvm.ctlz.i64"},
 	{INTRINS_CTTZ_I32, "llvm.cttz.i32"},
 	{INTRINS_CTTZ_I64, "llvm.cttz.i64"},
 	{INTRINS_PEXT_I32, "llvm.x86.bmi.pext.32"},
@@ -8625,9 +8635,11 @@ add_intrinsic (LLVMModuleRef module, int id)
 	case INTRINS_EXPECT_I1:
 		AddFunc2 (module, name, LLVMInt1Type (), LLVMInt1Type (), LLVMInt1Type ());
 		break;
+	case INTRINS_CTLZ_I32:
 	case INTRINS_CTPOP_I32:
 		AddFunc1 (module, name, LLVMInt32Type (), LLVMInt32Type ());
 		break;
+	case INTRINS_CTLZ_I64:
 	case INTRINS_CTPOP_I64:
 		AddFunc1 (module, name, LLVMInt64Type (), LLVMInt64Type ());
 		break;
diff --git a/src/mono/mono/mini/simd-intrinsics-netcore.c b/src/mono/mono/mini/simd-intrinsics-netcore.c
index abfe8e2..796406a 100644
--- a/src/mono/mono/mini/simd-intrinsics-netcore.c
+++ b/src/mono/mono/mini/simd-intrinsics-netcore.c
@@ -437,6 +437,11 @@ static guint16 popcnt_methods [] = {
 	SN_get_IsSupported
 };
 
+static guint16 lzcnt_methods [] = {
+	SN_LeadingZeroCount,
+	SN_get_IsSupported
+};
+
 static guint16 bmi1_methods [] = {
 	SN_TrailingZeroCount,
 	SN_get_IsSupported,
@@ -485,6 +490,31 @@ emit_x86_intrinsics (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature
 			return NULL;
 		}
 	}
+	if (!strcmp (class_name, "Lzcnt") || (!strcmp (class_name, "X64") && cmethod->klass->nested_in && !strcmp (m_class_get_name (cmethod->klass->nested_in), "Lzcnt"))) {
+		id = lookup_intrins (lzcnt_methods, sizeof (lzcnt_methods), cmethod);
+		if (id == -1)
+			return NULL;
+
+		supported = (get_cpu_features () & MONO_CPU_X86_LZCNT) != 0;
+		is_64bit = !strcmp (class_name, "X64");
+
+		switch (id) {
+		case SN_get_IsSupported:
+			EMIT_NEW_ICONST (cfg, ins, supported ? 1 : 0);
+			ins->type = STACK_I4;
+			return ins;
+		case SN_LeadingZeroCount:
+			if (!supported)
+				return NULL;
+			MONO_INST_NEW (cfg, ins, is_64bit ? OP_LZCNT64 : OP_LZCNT32);
+			ins->dreg = alloc_ireg (cfg);
+			ins->sreg1 = args [0]->dreg;
+			MONO_ADD_INS (cfg->cbb, ins);
+			return ins;
+		default:
+			return NULL;
+		}
+	}
 	if (!strcmp (class_name, "Bmi1") || (!strcmp (class_name, "X64") && cmethod->klass->nested_in && !strcmp (m_class_get_name (cmethod->klass->nested_in), "Bmi1"))) {
 		// We only support the subset used by corelib
 		if (m_class_get_image (cfg->method->klass) != mono_get_corlib ())
diff --git a/src/mono/mono/mini/simd-methods-netcore.h b/src/mono/mono/mini/simd-methods-netcore.h
index a4af28d..e15e237 100644
--- a/src/mono/mono/mini/simd-methods-netcore.h
+++ b/src/mono/mono/mini/simd-methods-netcore.h
@@ -5,6 +5,7 @@ METHOD(LessThan)
 METHOD(Min)
 METHOD(Max)
 METHOD(PopCount)
+METHOD(LeadingZeroCount)
 METHOD(get_Count)
 METHOD(get_IsHardwareAccelerated)
 METHOD(get_IsSupported)