From bf083b3beeb9a622017137c246d2cfa863056cc0 Mon Sep 17 00:00:00 2001

From: Nicolas Ojeda Bar <n.oje.bar@gmail.com>

Date: Tue, 22 Nov 2016 22:30:35 +0100

Subject: [PATCH 10/12] Fix immediates' range when adjusting/indexing sp

---

 asmcomp/riscv/arch.ml      |  3 +++

 asmcomp/riscv/emit.mlp     | 53 ++++++++++++++++++++++++++++++++++------------

 asmcomp/riscv/selection.ml |  2 +-

 3 files changed, 44 insertions(+), 14 deletions(-)

diff --git a/asmcomp/riscv/arch.ml b/asmcomp/riscv/arch.ml

index 61a38b1dd..22c807c49 100644

--- a/asmcomp/riscv/arch.ml

+++ b/asmcomp/riscv/arch.ml

@@ -32,6 +32,9 @@ let spacetime_node_hole_pointer_is_live_before = function

 type addressing_mode =

   | Iindexed of int                     (* reg + displ *)

+let is_immediate n =

+  (n <= 2047) && (n >= -2048)

+

 (* Sizes, endianness *)

 let big_endian = false

diff --git a/asmcomp/riscv/emit.mlp b/asmcomp/riscv/emit.mlp

index 6d0e3aefd..97c49ce80 100644

--- a/asmcomp/riscv/emit.mlp

+++ b/asmcomp/riscv/emit.mlp

@@ -93,6 +93,34 @@ let emit_stack r =

       let ofs = slot_offset s (register_class r) in `{emit_int ofs}(sp)`

   | _ -> fatal_error "Emit.emit_stack"

+(* Adjust sp by the given byte amount *)

+

+let emit_stack_adjustment = function

+  | 0 -> ()

+  | n when is_immediate n ->

+      `	addi	sp, sp, {emit_int n}\n`

+  | n ->

+      `	li	{emit_reg reg_tmp1}, {emit_int n}\n`;

+      `	add	sp, sp, {emit_reg reg_tmp1}\n`

+

+let emit_store src ofs =

+  if is_immediate ofs then

+    `	{emit_string stg}	{emit_reg src}, {emit_int ofs}(sp)\n`

+  else begin

+    `	li	{emit_reg reg_tmp1}, {emit_int ofs}\n`;

+    `	add	{emit_reg reg_tmp1}, sp, {emit_reg reg_tmp1}\n`;

+    `	{emit_string stg}	{emit_reg src}, 0({emit_reg reg_tmp1})\n`

+  end

+

+let emit_load dst ofs =

+  if is_immediate ofs then

+    `	{emit_string lg}	{emit_reg dst}, {emit_int ofs}(sp)\n`

+  else begin

+    `	li	{emit_reg reg_tmp1}, {emit_int ofs}\n`;

+    `	add	{emit_reg reg_tmp1}, sp, {emit_reg reg_tmp1}\n`;

+    `	{emit_string lg}	{emit_reg dst}, 0({emit_reg reg_tmp1})\n`

+  end

+

 (* Record live pointers at call points *)

 let record_frame_label ?label live raise_ dbg =

@@ -218,6 +246,7 @@ let name_for_specific = function

 (* Name of current function *)

 let function_name = ref ""

+

 (* Entry point for tail recursive calls *)

 let tailrec_entry_point = ref 0

@@ -234,12 +263,14 @@ let emit_instr i =

             `	mv      {emit_reg dst}, {emit_reg src}\n`

         | {loc = Reg _; typ = Float}, {loc = Reg _; typ = Float} ->

             `	fmv.d   {emit_reg dst}, {emit_reg src}\n`

-        | {loc = Reg _; typ = (Val | Int | Addr)}, {loc = Stack _} ->

-            `	{emit_string stg}	{emit_reg src}, {emit_stack dst}\n`

+        | {loc = Reg _; typ = (Val | Int | Addr)}, {loc = Stack s} ->

+            let ofs = slot_offset s (register_class dst) in

+            emit_store src ofs

         | {loc = Reg _; typ = Float}, {loc = Stack _} ->

             `	fsd	{emit_reg src}, {emit_stack dst}\n`

-        | {loc = Stack _; typ = (Val | Int | Addr)}, {loc = Reg _ } ->

-            `	{emit_string lg}	{emit_reg dst}, {emit_stack src}\n`

+        | {loc = Stack s; typ = (Val | Int | Addr)}, {loc = Reg _} ->

+            let ofs = slot_offset s (register_class src) in

+            emit_load dst ofs

         | {loc = Stack _; typ = Float}, {loc = Reg _} ->

             `	fld	{emit_reg dst}, {emit_stack src}\n`

         | _ ->

@@ -263,8 +294,7 @@ let emit_instr i =

       let n = frame_size() in

       if !contains_calls then

         `	{emit_string lg}	ra, {emit_int(n - size_addr)}(sp)\n`;

-      if n > 0 then

-        `	addi	sp, sp, {emit_int n}\n`;

+      emit_stack_adjustment n;

       `	jr	{emit_reg i.arg.(0)}\n`

   | Lop(Itailcall_imm {func; label_after = _}) ->

       if func = !function_name then begin

@@ -273,8 +303,7 @@ let emit_instr i =

         let n = frame_size() in

         if !contains_calls then

           `	{emit_string lg}	ra, {emit_int(n - size_addr)}(sp)\n`;

-        if n > 0 then

-          `	addi	sp, sp, {emit_int n}\n`;

+        emit_stack_adjustment n;

         `	tail	{emit_symbol func}\n`

       end

   | Lop(Iextcall{func; alloc = true; label_after = label}) ->

@@ -285,7 +314,7 @@ let emit_instr i =

       `	call	{emit_symbol func}\n`

   | Lop(Istackoffset n) ->

       assert (n mod 16 = 0);

-      `	addi	sp, sp, {emit_int (-n)}\n`;

+      emit_stack_adjustment (-n);

       stack_offset := !stack_offset + n

   | Lop(Iload(Single, Iindexed ofs)) ->

       `	flw	{emit_reg i.res.(0)}, {emit_int ofs}({emit_reg i.arg.(0)})\n`;

@@ -398,8 +427,7 @@ let emit_instr i =

       `	{emit_string lg}	ra, {emit_int(n - size_addr)}(sp)\n`

   | Lreturn ->

       let n = frame_size() in

-      if n > 0 then

-        `	addi	sp, sp, {emit_int n}\n`;

+      emit_stack_adjustment n;

       `	ret\n`

   | Llabel lbl ->

       `{emit_label lbl}:\n`

@@ -513,8 +541,7 @@ let fundecl fundecl =

   `	.align	2\n`;

   `{emit_symbol fundecl.fun_name}:\n`;

   let n = frame_size() in

-  if n > 0 then

-    `	addi	sp, sp, {emit_int(-n)}\n`;

+  emit_stack_adjustment (-n);

   if !contains_calls then

     `	{emit_string stg}	ra, {emit_int(n - size_addr)}(sp)\n`;

   `{emit_label !tailrec_entry_point}:\n`;

diff --git a/asmcomp/riscv/selection.ml b/asmcomp/riscv/selection.ml

index ad2b26e9b..283233679 100644

--- a/asmcomp/riscv/selection.ml

+++ b/asmcomp/riscv/selection.ml

@@ -22,7 +22,7 @@ class selector = object (self)

 inherit Selectgen.selector_generic as super

-method is_immediate n = (n <= 0x7FF) && (n >= -0x800)

+method is_immediate n = is_immediate n

 method select_addressing _ = function

   | Cop(Cadda, [arg; Cconst_int n]) when self#is_immediate n ->

-- 

2.13.2