ac: add ac_build_frex_exp() helper ans 16-bit/32-bit support

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

src/amd/common/ac_llvm_build.c

@@ -3927,6 +3927,30 @@ ac_build_shuffle(struct ac_llvm_context *ctx, LLVMValueRef src, LLVMValueRef ind
 		  AC_FUNC_ATTR_CONVERGENT);
 }
 
+LLVMValueRef
+ac_build_frexp_exp(struct ac_llvm_context *ctx, LLVMValueRef src0,
+		   unsigned bitsize)
+{
+	LLVMTypeRef type;
+	char *intr;
+
+	if (bitsize == 16) {
+		intr = "llvm.amdgcn.frexp.exp.i16.f16";
+		type = ctx->i16;
+	} else if (bitsize == 32) {
+		intr = "llvm.amdgcn.frexp.exp.i32.f32";
+		type = ctx->i32;
+	} else {
+		intr = "llvm.amdgcn.frexp.exp.i32.f64";
+		type = ctx->i64;
+	}
+
+	LLVMValueRef params[] = {
+		src0,
+	};
+	return ac_build_intrinsic(ctx, intr, type, params, 1,
+				  AC_FUNC_ATTR_READNONE);
+}
 LLVMValueRef
 ac_build_frexp_mant(struct ac_llvm_context *ctx, LLVMValueRef src0,
 		    unsigned bitsize)

src/amd/common/ac_llvm_build.h

@@ -677,6 +677,10 @@ ac_build_quad_swizzle(struct ac_llvm_context *ctx, LLVMValueRef src,
 LLVMValueRef
 ac_build_shuffle(struct ac_llvm_context *ctx, LLVMValueRef src, LLVMValueRef index);
 
+LLVMValueRef
+ac_build_frexp_exp(struct ac_llvm_context *ctx, LLVMValueRef src0,
+		   unsigned bitsize);
+
 LLVMValueRef
 ac_build_frexp_mant(struct ac_llvm_context *ctx, LLVMValueRef src0,
 		    unsigned bitsize);

src/amd/common/ac_nir_to_llvm.c

@@ -803,9 +803,11 @@ static void visit_alu(struct ac_nir_context *ctx, const nir_alu_instr *instr)
 		break;
 	case nir_op_frexp_exp:
 		src[0] = ac_to_float(&ctx->ac, src[0]);
-		result = ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.frexp.exp.i32.f64",
-					    ctx->ac.i32, src, 1, AC_FUNC_ATTR_READNONE);
-
+		result = ac_build_frexp_exp(&ctx->ac, src[0],
+					    ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])));
+		if (ac_get_elem_bits(&ctx->ac, LLVMTypeOf(src[0])) == 16)
+			result = LLVMBuildSExt(ctx->ac.builder, result,
+					       ctx->ac.i32, "");
 		break;
 	case nir_op_frexp_sig:
 		src[0] = ac_to_float(&ctx->ac, src[0]);