Skip to content

R
riscv-gcc-1
Commit 36be1dee by Richard Sandiford Committed by Richard Sandiford
Options

re PR target/51931 (No support for MIPS16 long branches) 

gcc/
	PR target/51931
	* config/mips/mips-protos.h (mips_strip_unspec_address): Declare.
	* config/mips/mips.c (mips_strip_unspec_address): Make extern.
	(mips16_rewrite_pool_constant): Make a copy of the pool constant
	before adding to a PC-relative table.
	(mips16_lay_out_constants): Add a SPLIT_P parameter.
	(mips16_load_branch_target, mips16_split_long_branches): New functions.
	(mips_reorg): Update call to mips16_lay_out_constants.
	Call mips16_split_long_branches.
	* config/mips/predicates.md (pc_or_label_operand): Delete.
	* config/mips/mips.md (length): Add a calculation for MIPS16 branches.
	Move the extended_mips16 handling further down.
	(*branch_equality<mode>_mips16): Replace use pc_or_label_operand
	with explicit label_ref and pc.  Follow the usual operand numbering.
	(*branch_equality<mode>_mips16_inverted): New pattern.
	(*jump_mips16): Add length attribute.
	(indirect_jump_and_restore_<mode>): New pattern.
	(consttable_int): Call mips_strip_unspec_address on the operand.

gcc/testsuite/
	PR target/51931
	* gcc.c-torture/compile/20001226-1.c: Remove nomips16 attribute.
	* g++.dg/opt/longbranch1.C: Likewise.

From-SVN: r190104
parent b5b071a5
Showing with 313 additions and 53 deletions
gcc/ChangeLog
2012-08-02 Richard Sandiford <rdsandiford@googlemail.com>
PR target/51931
* config/mips/mips-protos.h (mips_strip_unspec_address): Declare.
* config/mips/mips.c (mips_strip_unspec_address): Make extern.
(mips16_rewrite_pool_constant): Make a copy of the pool constant
before adding to a PC-relative table.
(mips16_lay_out_constants): Add a SPLIT_P parameter.
(mips16_load_branch_target, mips16_split_long_branches): New functions.
(mips_reorg): Update call to mips16_lay_out_constants.
Call mips16_split_long_branches.
* config/mips/predicates.md (pc_or_label_operand): Delete.
* config/mips/mips.md (length): Add a calculation for MIPS16 branches.
Move the extended_mips16 handling further down.
(*branch_equality<mode>_mips16): Replace use pc_or_label_operand
with explicit label_ref and pc. Follow the usual operand numbering.
(*branch_equality<mode>_mips16_inverted): New pattern.
(*jump_mips16): Add length attribute.
(indirect_jump_and_restore_<mode>): New pattern.
(consttable_int): Call mips_strip_unspec_address on the operand.
2012-08-02 Richard Sandiford <rdsandiford@googlemail.com>
* recog.c (split_insn): Copy the original SET_SRC before using
it as a note.
......
gcc/config/mips/mips-protos.h
......@@ -190,6 +190,7 @@ extern rtx mips_pic_base_register (rtx);
extern rtx mips_got_load (rtx, rtx, enum mips_symbol_type);
extern bool mips_split_symbol (rtx, rtx, enum machine_mode, rtx *);
extern rtx mips_unspec_address (rtx, enum mips_symbol_type);
extern rtx mips_strip_unspec_address (rtx);
extern void mips_move_integer (rtx, rtx, unsigned HOST_WIDE_INT);
extern bool mips_legitimize_move (enum machine_mode, rtx, rtx);
......
gcc/config/mips/mips.c
......@@ -2563,7 +2563,7 @@ mips_unspec_address (rtx address, enum mips_symbol_type symbol_type)
/* If OP is an UNSPEC address, return the address to which it refers,
otherwise return OP itself. */
static rtx
rtx
mips_strip_unspec_address (rtx op)
{
rtx base, offset;
......@@ -14070,7 +14070,7 @@ mips16_rewrite_pool_constant (struct mips16_constant_pool *pool, rtx *x)
split_const (*x, &base, &offset);
if (GET_CODE (base) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (base))
{
label = mips16_add_constant (pool, get_pool_constant (base),
label = mips16_add_constant (pool, copy_rtx (get_pool_constant (base)),
get_pool_mode (base));
base = gen_rtx_LABEL_REF (Pmode, label);
*x = mips_unspec_address_offset (base, offset, SYMBOL_PC_RELATIVE);
......@@ -14126,10 +14126,11 @@ mips_cfg_in_reorg (void)
|| TARGET_RELAX_PIC_CALLS);
}
/* Build MIPS16 constant pools. */
/* Build MIPS16 constant pools. Split the instructions if SPLIT_P,
otherwise assume that they are already split. */
static void
mips16_lay_out_constants (void)
mips16_lay_out_constants (bool split_p)
{
struct mips16_constant_pool pool;
struct mips16_rewrite_pool_refs_info info;
......@@ -14138,10 +14139,13 @@ mips16_lay_out_constants (void)
if (!TARGET_MIPS16_PCREL_LOADS)
return;
if (mips_cfg_in_reorg ())
split_all_insns ();
else
split_all_insns_noflow ();
if (split_p)
{
if (mips_cfg_in_reorg ())
split_all_insns ();
else
split_all_insns_noflow ();
}
barrier = 0;
memset (&pool, 0, sizeof (pool));
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
......@@ -15490,6 +15494,110 @@ mips_df_reorg (void)
df_finish_pass (false);
}
/* Emit code to load LABEL_REF SRC into MIPS16 register DEST. This is
called very late in mips_reorg, but the caller is required to run
mips16_lay_out_constants on the result. */
static void
mips16_load_branch_target (rtx dest, rtx src)
{
if (TARGET_ABICALLS && !TARGET_ABSOLUTE_ABICALLS)
{
rtx page, low;
if (mips_cfun_has_cprestore_slot_p ())
mips_emit_move (dest, mips_cprestore_slot (dest, true));
else
mips_emit_move (dest, pic_offset_table_rtx);
page = mips_unspec_address (src, SYMBOL_GOTOFF_PAGE);
low = mips_unspec_address (src, SYMBOL_GOT_PAGE_OFST);
emit_insn (gen_rtx_SET (VOIDmode, dest,
PMODE_INSN (gen_unspec_got, (dest, page))));
emit_insn (gen_rtx_SET (VOIDmode, dest,
gen_rtx_LO_SUM (Pmode, dest, low)));
}
else
{
src = mips_unspec_address (src, SYMBOL_ABSOLUTE);
mips_emit_move (dest, src);
}
}
/* If we're compiling a MIPS16 function, look for and split any long branches.
This must be called after all other instruction modifications in
mips_reorg. */
static void
mips16_split_long_branches (void)
{
bool something_changed;
if (!TARGET_MIPS16)
return;
/* Loop until the alignments for all targets are sufficient. */
do
{
rtx insn;
shorten_branches (get_insns ());
something_changed = false;
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
if (JUMP_P (insn)
&& USEFUL_INSN_P (insn)
&& get_attr_length (insn) > 8)
{
rtx old_label, new_label, temp, saved_temp;
rtx target, jump, jump_sequence;
start_sequence ();
/* Free up a MIPS16 register by saving it in $1. */
saved_temp = gen_rtx_REG (Pmode, AT_REGNUM);
temp = gen_rtx_REG (Pmode, GP_REG_FIRST + 2);
emit_move_insn (saved_temp, temp);
/* Load the branch target into TEMP. */
old_label = JUMP_LABEL (insn);
target = gen_rtx_LABEL_REF (Pmode, old_label);
mips16_load_branch_target (temp, target);
/* Jump to the target and restore the register's
original value. */
jump = emit_jump_insn (PMODE_INSN (gen_indirect_jump_and_restore,
(temp, temp, saved_temp)));
JUMP_LABEL (jump) = old_label;
LABEL_NUSES (old_label)++;
/* Rewrite any symbolic references that are supposed to use
a PC-relative constant pool. */
mips16_lay_out_constants (false);
if (simplejump_p (insn))
/* We're going to replace INSN with a longer form. */
new_label = NULL_RTX;
else
{
/* Create a branch-around label for the original
instruction. */
new_label = gen_label_rtx ();
emit_label (new_label);
}
jump_sequence = get_insns ();
end_sequence ();
emit_insn_after (jump_sequence, insn);
if (new_label)
invert_jump (insn, new_label, false);
else
delete_insn (insn);
something_changed = true;
}
}
while (something_changed);
}
/* Implement TARGET_MACHINE_DEPENDENT_REORG. */
static void
......@@ -15500,7 +15608,7 @@ mips_reorg (void)
to date if the CFG is available. */
if (mips_cfg_in_reorg ())
compute_bb_for_insn ();
mips16_lay_out_constants ();
mips16_lay_out_constants (true);
if (mips_cfg_in_reorg ())
{
mips_df_reorg ();
......@@ -15519,6 +15627,7 @@ mips_reorg (void)
/* The expansion could invalidate some of the VR4130 alignment
optimizations, but this should be an extremely rare case anyhow. */
mips_reorg_process_insns ();
mips16_split_long_branches ();
}
/* Implement TARGET_ASM_OUTPUT_MI_THUNK. Generate rtl rather than asm text
......@@ -15639,7 +15748,7 @@ mips_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
insn = get_insns ();
insn_locators_alloc ();
split_all_insns_noflow ();
mips16_lay_out_constants ();
mips16_lay_out_constants (true);
shorten_branches (insn);
final_start_function (insn, file, 1);
final (insn, file, 1);
......
gcc/config/mips/mips.md
......@@ -402,11 +402,7 @@
;; Length of instruction in bytes.
(define_attr "length" ""
(cond [(and (eq_attr "extended_mips16" "yes")
(match_test "TARGET_MIPS16"))
(const_int 8)
;; Direct branch instructions have a range of [-0x20000,0x1fffc],
(cond [;; Direct branch instructions have a range of [-0x20000,0x1fffc],
;; relative to the address of the delay slot. If a branch is
;; outside this range, we have a choice of two sequences.
;; For PIC, an out-of-range branch like:
......@@ -431,14 +427,21 @@
;; using la/jr in this case too, but we do not do so at
;; present.
;;
;; Note that this value does not account for the delay slot
;; The value we specify here does not account for the delay slot
;; instruction, whose length is added separately. If the RTL
;; pattern has no explicit delay slot, mips_adjust_insn_length
;; will add the length of the implicit nop. The values for
;; forward and backward branches will be different as well.
(eq_attr "type" "branch")
;; will add the length of the implicit nop. The range of
;; [-0x20000, 0x1fffc] from the address of the delay slot
;; therefore translates to a range of:
;;
;; [-(0x20000 - sizeof (branch)), 0x1fffc - sizeof (slot)]
;; == [-0x1fffc, 0x1fff8]
;;
;; from the shorten_branches reference address.
(and (eq_attr "type" "branch")
(not (match_test "TARGET_MIPS16")))
(cond [(and (le (minus (match_dup 0) (pc)) (const_int 131064))
(le (minus (pc) (match_dup 0)) (const_int 131068)))
(le (minus (pc) (match_dup 0)) (const_int 131068)))
(const_int 4)
;; The non-PIC case: branch, first delay slot, and J.
......@@ -453,6 +456,100 @@
;; of an insn.
(const_int MAX_PIC_BRANCH_LENGTH))
;; An unextended MIPS16 branch has a range of [-0x100, 0xfe]
;; from the address of the following instruction, which leads
;; to a range of:
;;
;; [-(0x100 - sizeof (branch)), 0xfe]
;; == [-0xfe, 0xfe]
;;
;; from the shorten_branches reference address. Extended branches
;; likewise have a range of [-0x10000, 0xfffe] from the address
;; of the following instruction, which leads to a range of:
;;
;; [-(0x10000 - sizeof (branch)), 0xfffe]
;; == [-0xfffc, 0xfffe]
;;
;; from the reference address.
;;
;; When a branch is out of range, mips_reorg splits it into a form
;; that uses in-range branches. There are four basic sequences:
;;
;; (1) Absolute addressing with a readable text segment
;; (32-bit addresses):
;;
;; b... foo 2 bytes
;; move $1,$2 2 bytes
;; lw $2,label 2 bytes
;; jr $2 2 bytes
;; move $2,$1 2 bytes
;; .align 2 0 or 2 bytes
;; label:
;; .word target 4 bytes
;; foo:
;; (16 bytes in the worst case)
;;
;; (2) Absolute addressing with a readable text segment
;; (64-bit addresses):
;;
;; b... foo 2 bytes
;; move $1,$2 2 bytes
;; ld $2,label 2 bytes
;; jr $2 2 bytes
;; move $2,$1 2 bytes
;; .align 3 0 to 6 bytes
;; label:
;; .dword target 8 bytes
;; foo:
;; (24 bytes in the worst case)
;;
;; (3) Absolute addressing without a readable text segment
;; (which requires 32-bit addresses at present):
;;
;; b... foo 2 bytes
;; move $1,$2 2 bytes
;; lui $2,%hi(target) 4 bytes
;; sll $2,8 2 bytes
;; sll $2,8 2 bytes
;; addiu $2,%lo(target) 4 bytes
;; jr $2 2 bytes
;; move $2,$1 2 bytes
;; foo:
;; (20 bytes)
;;
;; (4) PIC addressing (which requires 32-bit addresses at present):
;;
;; b... foo 2 bytes
;; move $1,$2 2 bytes
;; lw $2,cprestore 0, 2 or 4 bytes
;; lw $2,%got(target)($2) 4 bytes
;; addiu $2,%lo(target) 4 bytes
;; jr $2 2 bytes
;; move $2,$1 2 bytes
;; foo:
;; (20 bytes in the worst case)
;;
;; Note that the conditions test adjusted lengths, whereas the
;; result is an unadjusted length, and is thus twice the true value.
(and (eq_attr "type" "branch")
(match_test "TARGET_MIPS16"))
(cond [(and (le (minus (match_dup 0) (pc)) (const_int 254))
(le (minus (pc) (match_dup 0)) (const_int 254)))
(const_int 4)
(and (le (minus (match_dup 0) (pc)) (const_int 65534))
(le (minus (pc) (match_dup 0)) (const_int 65532)))
(const_int 8)
(and (match_test "TARGET_ABICALLS")
(not (match_test "TARGET_ABSOLUTE_ABICALLS")))
(const_int 40)
(match_test "Pmode == SImode")
(const_int 32)
] (const_int 48))
(and (eq_attr "extended_mips16" "yes")
(match_test "TARGET_MIPS16"))
(const_int 8)
;; "Ghost" instructions occupy no space.
(eq_attr "type" "ghost")
(const_int 0)
......@@ -5400,28 +5497,29 @@
(define_insn "*branch_equality<mode>_mips16"
[(set (pc)
(if_then_else
(match_operator 0 "equality_operator"
[(match_operand:GPR 1 "register_operand" "d,t")
(match_operator 1 "equality_operator"
[(match_operand:GPR 2 "register_operand" "d,t")
(const_int 0)])
(label_ref (match_operand 0 "" ""))
(pc)))]
"TARGET_MIPS16"
"@
b%C1z\t%2,%0
bt%C1z\t%0"
[(set_attr "type" "branch")])
(define_insn "*branch_equality<mode>_mips16_inverted"
[(set (pc)
(if_then_else
(match_operator 1 "equality_operator"
[(match_operand:GPR 2 "register_operand" "d,t")
(const_int 0)])
(match_operand 2 "pc_or_label_operand" "")
(match_operand 3 "pc_or_label_operand" "")))]
(pc)
(label_ref (match_operand 0 "" ""))))]
"TARGET_MIPS16"
{
if (operands[2] != pc_rtx)
{
if (which_alternative == 0)
return "b%C0z\t%1,%2";
else
return "bt%C0z\t%2";
}
else
{
if (which_alternative == 0)
return "b%N0z\t%1,%3";
else
return "bt%N0z\t%3";
}
}
"@
b%N1z\t%2,%0
bt%N1z\t%0"
[(set_attr "type" "branch")])
(define_expand "cbranch<mode>4"
......@@ -5717,7 +5815,30 @@
(label_ref (match_operand 0 "" "")))]
"TARGET_MIPS16"
"b\t%l0"
[(set_attr "type" "branch")])
[(set_attr "type" "branch")
(set (attr "length")
;; This calculation is like the normal branch one, but the
;; range of the unextended instruction is [-0x800, 0x7fe] rather
;; than [-0x100, 0xfe]. This translates to a range of:
;;
;; [-(0x800 - sizeof (branch)), 0x7fe]
;; == [-0x7fe, 0x7fe]
;;
;; from the shorten_branches reference address. Long-branch
;; sequences will replace this one, so the minimum length
;; is one instruction shorter than for conditional branches.
(cond [(and (le (minus (match_dup 0) (pc)) (const_int 2046))
(le (minus (pc) (match_dup 0)) (const_int 2046)))
(const_int 4)
(and (le (minus (match_dup 0) (pc)) (const_int 65534))
(le (minus (pc) (match_dup 0)) (const_int 65532)))
(const_int 8)
(and (match_test "TARGET_ABICALLS")
(not (match_test "TARGET_ABSOLUTE_ABICALLS")))
(const_int 36)
(match_test "Pmode == SImode")
(const_int 28)
] (const_int 44)))])
(define_expand "indirect_jump"
[(set (pc) (match_operand 0 "register_operand"))]
......@@ -5735,6 +5856,18 @@
[(set_attr "type" "jump")
(set_attr "mode" "none")])
;; A combined jump-and-move instruction, used for MIPS16 long-branch
;; sequences. Having a dedicated pattern is more convenient than
;; creating a SEQUENCE for this special case.
(define_insn "indirect_jump_and_restore_<mode>"
[(set (pc) (match_operand:P 1 "register_operand" "d"))
(set (match_operand:P 0 "register_operand" "=d")
(match_operand:P 2 "register_operand" "y"))]
""
"%(%<jr\t%1\;move\t%0,%2%>%)"
[(set_attr "type" "multi")
(set_attr "extended_mips16" "yes")])
(define_expand "tablejump"
[(set (pc)
(match_operand 0 "register_operand"))
......@@ -6549,7 +6682,8 @@
UNSPEC_CONSTTABLE_INT)]
"TARGET_MIPS16"
{
assemble_integer (operands[0], INTVAL (operands[1]),
assemble_integer (mips_strip_unspec_address (operands[0]),
INTVAL (operands[1]),
BITS_PER_UNIT * INTVAL (operands[1]), 1);
return "";
}
......
gcc/config/mips/predicates.md
......@@ -139,9 +139,6 @@
(match_operand 0 "hilo_operand")
(match_operand 0 "register_operand")))
(define_special_predicate "pc_or_label_operand"
(match_code "pc,label_ref"))
(define_predicate "const_call_insn_operand"
(match_code "const,symbol_ref,label_ref")
{
......
gcc/testsuite/ChangeLog
2012-08-02 Richard Sandiford <rdsandiford@googlemail.com>
PR target/51931
* gcc.c-torture/compile/20001226-1.c: Remove nomips16 attribute.
* g++.dg/opt/longbranch1.C: Likewise.
2012-08-02 Marc Glisse <marc.glisse@inria.fr>
PR tree-optimization/53805
......
gcc/testsuite/g++.dg/opt/longbranch1.C
......@@ -26,10 +26,6 @@
muchcode; muchcode; muchcode; muchcode; muchcode; muchcode; \
muchcode; muchcode; muchcode; muchcode; muchcode; muchcode
#ifdef __mips
/* See PR 51931. */
__attribute__((nomips16))
#endif
int
main (int argc, char **argv)
{
......
gcc/testsuite/gcc.c-torture/compile/20001226-1.c
......@@ -21,10 +21,6 @@
#define C1024(x,y) C256(x,y) C256(x+16,y) C256(x+32,y) C256(x+48,y)
#define C4096(x,y) C1024(x,y) C1024(x,y+16) C1024(x,y+32) C1024(x,y+48)
#ifdef __mips
/* See PR 51931. */
__attribute__((nomips16))
#endif
unsigned foo(int x[64], int y[64])
{
C4096(x,y);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment