From 7002c94a63c58aa0ac5a5d74b1fffd1511aeb699 Mon Sep 17 00:00:00 2001
From: gingerBill <bill@gingerbill.org>
Date: Wed, 25 May 2022 23:34:41 +0100
Subject: [PATCH] Add `intrinsics.simd_select`

---
 core/simd/simd.odin           |  1 +
 src/check_builtin.cpp         | 51 +++++++++++++++++++++++++++++++++++
 src/checker_builtin_procs.hpp |  2 ++
 src/llvm_backend_proc.cpp     | 12 +++++++++
 4 files changed, 66 insertions(+)

diff --git a/core/simd/simd.odin b/core/simd/simd.odin
index b5207e154..1819f3951 100644
--- a/core/simd/simd.odin
+++ b/core/simd/simd.odin
@@ -74,6 +74,7 @@ reduce_xor         :: intrinsics.simd_reduce_xor
 
 swizzle :: builtin.swizzle
 shuffle :: intrinsics.simd_shuffle
+select :: intrinsics.simd_select
 
 splat :: #force_inline proc "contextless" ($T: typeid/#simd[$LANES]$E, value: E) -> T {
 	return T{0..<LANES = value}
diff --git a/src/check_builtin.cpp b/src/check_builtin.cpp
index 064edd3b7..eaf71fdab 100644
--- a/src/check_builtin.cpp
+++ b/src/check_builtin.cpp
@@ -815,6 +815,57 @@ bool check_builtin_simd_operation(CheckerContext *c, Operand *operand, Ast *call
 			return true;
 		}
 
+	case BuiltinProc_simd_select:
+		{
+			Operand cond = {};
+			check_expr(c, &cond, ce->args[0]); if (cond.mode == Addressing_Invalid) { return false; }
+
+			if (!is_type_simd_vector(cond.type)) {
+				error(cond.expr, "'%.*s' expected a simd vector boolean type", LIT(builtin_name));
+				return false;
+			}
+			if (!is_type_boolean(base_array_type(cond.type))) {
+				error(cond.expr, "'%.*s' expected a simd vector boolean type", LIT(builtin_name));
+				return false;
+			}
+
+			Operand x = {};
+			Operand y = {};
+			check_expr(c, &x, ce->args[1]); if (x.mode == Addressing_Invalid) { return false; }
+			check_expr_with_type_hint(c, &y, ce->args[2], x.type); if (y.mode == Addressing_Invalid) { return false; }
+			convert_to_typed(c, &y, x.type);
+			if (!is_type_simd_vector(x.type)) {
+				error(x.expr, "'%.*s' expected a simd vector type", LIT(builtin_name));
+				return false;
+			}
+			if (!is_type_simd_vector(y.type)) {
+				error(y.expr, "'%.*s' expected a simd vector type", LIT(builtin_name));
+				return false;
+			}
+			if (!are_types_identical(x.type, y.type)) {
+				gbString xs = type_to_string(x.type);
+				gbString ys = type_to_string(y.type);
+				error(x.expr, "'%.*s' expected 2 results of the same type, got '%s' vs '%s'", LIT(builtin_name), xs, ys);
+				gb_string_free(ys);
+				gb_string_free(xs);
+				return false;
+			}
+
+			if (cond.type->SimdVector.count != x.type->SimdVector.count) {
+				error(x.expr, "'%.*s' expected condition vector to match the length of the result lengths, got '%lld' vs '%lld'",
+				      LIT(builtin_name),
+				      cast(long long)cond.type->SimdVector.count,
+				      cast(long long)x.type->SimdVector.count);
+				return false;
+			}
+
+
+			operand->mode = Addressing_Value;
+			operand->type = x.type;
+			return true;
+		}
+
+
 
 	// case BuiltinProc_simd_rotate_left:
 	// 	{
diff --git a/src/checker_builtin_procs.hpp b/src/checker_builtin_procs.hpp
index 722bbec84..2fb355e91 100644
--- a/src/checker_builtin_procs.hpp
+++ b/src/checker_builtin_procs.hpp
@@ -159,6 +159,7 @@ BuiltinProc__simd_begin,
 	BuiltinProc_simd_reduce_xor,
 
 	BuiltinProc_simd_shuffle,
+	BuiltinProc_simd_select,
 BuiltinProc__simd_end,
 	
 	// Platform specific intrinsics
@@ -421,6 +422,7 @@ gb_global BuiltinProc builtin_procs[BuiltinProc_COUNT] = {
 	{STR_LIT("simd_reduce_xor"),         1, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 
 	{STR_LIT("simd_shuffle"), 3, false, Expr_Expr, BuiltinProcPkg_intrinsics},
+	{STR_LIT("simd_select"),  3, false, Expr_Expr, BuiltinProcPkg_intrinsics},
 	{STR_LIT(""), 0, false, Expr_Stmt, BuiltinProcPkg_intrinsics},
 
 
diff --git a/src/llvm_backend_proc.cpp b/src/llvm_backend_proc.cpp
index 1b5d15d9b..7a86427d4 100644
--- a/src/llvm_backend_proc.cpp
+++ b/src/llvm_backend_proc.cpp
@@ -1296,6 +1296,18 @@ lbValue lb_build_builtin_simd_proc(lbProcedure *p, Ast *expr, TypeAndValue const
 			res.value = LLVMBuildShuffleVector(p->builder, arg0.value, arg1.value, mask, "");
 			return res;
 		}
+
+	case BuiltinProc_simd_select:
+		{
+			LLVMValueRef cond = arg0.value;
+			LLVMValueRef x = lb_build_expr(p, ce->args[1]).value;
+			LLVMValueRef y = lb_build_expr(p, ce->args[2]).value;
+
+			cond = LLVMBuildICmp(p->builder, LLVMIntNE, cond, LLVMConstNull(LLVMTypeOf(cond)), "");
+			res.value = LLVMBuildSelect(p->builder, cond, x, y, "");
+			return res;
+		}
+
 	}
 	GB_PANIC("Unhandled simd intrinsic: '%.*s'", LIT(builtin_procs[builtin_id].name));