From 371c35e5bb19989953e371be924fb0b908407c47 Mon Sep 17 00:00:00 2001
From: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Date: Fri, 14 Sep 2018 12:52:32 +0200
Subject: [PATCH] ac: add ac_build_bit_count() helper

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
---
 src/amd/common/ac_llvm_build.c  | 28 ++++++++++++++++++++++++++++
 src/amd/common/ac_llvm_build.h  |  2 ++
 src/amd/common/ac_nir_to_llvm.c |  7 +------
 3 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c
index 1f5112e9929..4fbe0ddb9c5 100644
--- a/src/amd/common/ac_llvm_build.c
+++ b/src/amd/common/ac_llvm_build.c
@@ -2107,6 +2107,34 @@ LLVMValueRef ac_build_fsign(struct ac_llvm_context *ctx, LLVMValueRef src0,
 	return val;
 }
 
+LLVMValueRef ac_build_bit_count(struct ac_llvm_context *ctx, LLVMValueRef src0)
+{
+	LLVMValueRef result;
+	unsigned bitsize;
+
+	bitsize = ac_get_elem_bits(ctx, LLVMTypeOf(src0));
+
+	switch (bitsize) {
+	case 64:
+		result = ac_build_intrinsic(ctx, "llvm.ctpop.i64", ctx->i64,
+					    (LLVMValueRef []) { src0 }, 1,
+					    AC_FUNC_ATTR_READNONE);
+
+		result = LLVMBuildTrunc(ctx->builder, result, ctx->i32, "");
+		break;
+	case 32:
+		result = ac_build_intrinsic(ctx, "llvm.ctpop.i32", ctx->i32,
+					    (LLVMValueRef []) { src0 }, 1,
+					    AC_FUNC_ATTR_READNONE);
+		break;
+	default:
+		unreachable(!"invalid bitsize");
+		break;
+	}
+
+	return result;
+}
+
 #define AC_EXP_TARGET		0
 #define AC_EXP_ENABLED_CHANNELS 1
 #define AC_EXP_OUT0		2
diff --git a/src/amd/common/ac_llvm_build.h b/src/amd/common/ac_llvm_build.h
index 0d261bae097..98a61a24054 100644
--- a/src/amd/common/ac_llvm_build.h
+++ b/src/amd/common/ac_llvm_build.h
@@ -424,6 +424,8 @@ LLVMValueRef ac_build_isign(struct ac_llvm_context *ctx, LLVMValueRef src0,
 LLVMValueRef ac_build_fsign(struct ac_llvm_context *ctx, LLVMValueRef src0,
 			    unsigned bitsize);
 
+LLVMValueRef ac_build_bit_count(struct ac_llvm_context *ctx, LLVMValueRef src0);
+
 void ac_optimize_vs_outputs(struct ac_llvm_context *ac,
 			    LLVMValueRef main_fn,
 			    uint8_t *vs_output_param_offset,
diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index a3f26ab46c9..d79ff4399b1 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -839,12 +839,7 @@ static void visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
 		result = ac_build_intrinsic(&ctx->ac, "llvm.bitreverse.i32", ctx->ac.i32, src, 1, AC_FUNC_ATTR_READNONE);
 		break;
 	case nir_op_bit_count:
-		if (ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])) == 32)
-			result = ac_build_intrinsic(&ctx->ac, "llvm.ctpop.i32", ctx->ac.i32, src, 1, AC_FUNC_ATTR_READNONE);
-		else {
-			result = ac_build_intrinsic(&ctx->ac, "llvm.ctpop.i64", ctx->ac.i64, src, 1, AC_FUNC_ATTR_READNONE);
-			result = LLVMBuildTrunc(ctx->ac.builder, result, ctx->ac.i32, "");
-		}
+		result = ac_build_bit_count(&ctx->ac, src[0]);
 		break;
 	case nir_op_vec2:
 	case nir_op_vec3: