--- /dev/null
+From 0dbdfb7918d0b0cfcb8883b24c1291574bf5bb7c Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Tue, 2 Apr 2019 14:32:42 -0700
+Subject: [PATCH] gas: use literals/const16 for xtensa loop relaxation
+
+Loop opcode relaxation that uses addi/addmi doesn't work well with other
+relaxations that may cause code movement. Instead of encoding fixed loop
+end offset in the relaxed sequence use l32r or a pair of const16 to load
+loop end address. This way the address of the loop end gets a relocation
+record and it gets updated appropriately.
+
+gas/
+2019-04-02 Max Filippov <jcmvbkbc@gmail.com>
+
+ * config/tc-xtensa.c (convert_frag_immed): Drop
+ convert_frag_immed_finish_loop invocation.
+ (convert_frag_immed_finish_loop): Drop declaration and
+ definition.
+ * config/xtensa-relax.c (widen_spec_list): Replace loop
+ widening that uses addi/addmi with widening that uses l32r
+ and const16.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+ gas/config/tc-xtensa.c | 120 ----------------------------------------------
+ gas/config/xtensa-relax.c | 77 ++++++++++++++++++++---------
+ 2 files changed, 55 insertions(+), 142 deletions(-)
+
+diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
+index 3bdbbc931cfc..0cc06361cf6f 100644
+--- a/gas/config/tc-xtensa.c
++++ b/gas/config/tc-xtensa.c
+@@ -10668,7 +10668,6 @@ convert_frag_fill_nop (fragS *fragP)
+ static fixS *fix_new_exp_in_seg
+ (segT, subsegT, fragS *, int, int, expressionS *, int,
+ bfd_reloc_code_real_type);
+-static void convert_frag_immed_finish_loop (segT, fragS *, TInsn *);
+
+ static void
+ convert_frag_immed (segT segP,
+@@ -10910,9 +10909,6 @@ convert_frag_immed (segT segP,
+ }
+ }
+
+- if (expanded && xtensa_opcode_is_loop (isa, orig_tinsn.opcode) == 1)
+- convert_frag_immed_finish_loop (segP, fragP, &orig_tinsn);
+-
+ if (expanded && is_direct_call_opcode (orig_tinsn.opcode))
+ {
+ /* Add an expansion note on the expanded instruction. */
+@@ -10949,122 +10945,6 @@ fix_new_exp_in_seg (segT new_seg,
+ }
+
+
+-/* Relax a loop instruction so that it can span loop >256 bytes.
+-
+- loop as, .L1
+- .L0:
+- rsr as, LEND
+- wsr as, LBEG
+- addi as, as, lo8 (label-.L1)
+- addmi as, as, mid8 (label-.L1)
+- wsr as, LEND
+- isync
+- rsr as, LCOUNT
+- addi as, as, 1
+- .L1:
+- <<body>>
+- label:
+-*/
+-
+-static void
+-convert_frag_immed_finish_loop (segT segP, fragS *fragP, TInsn *tinsn)
+-{
+- TInsn loop_insn;
+- TInsn addi_insn;
+- TInsn addmi_insn;
+- unsigned long target;
+- static xtensa_insnbuf insnbuf = NULL;
+- unsigned int loop_length, loop_length_hi, loop_length_lo;
+- xtensa_isa isa = xtensa_default_isa;
+- addressT loop_offset;
+- addressT addi_offset = 9;
+- addressT addmi_offset = 12;
+- fragS *next_fragP;
+- int target_count;
+-
+- if (!insnbuf)
+- insnbuf = xtensa_insnbuf_alloc (isa);
+-
+- /* Get the loop offset. */
+- loop_offset = get_expanded_loop_offset (tinsn->opcode);
+-
+- /* Validate that there really is a LOOP at the loop_offset. Because
+- loops are not bundleable, we can assume that the instruction will be
+- in slot 0. */
+- tinsn_from_chars (&loop_insn, fragP->fr_opcode + loop_offset, 0);
+- tinsn_immed_from_frag (&loop_insn, fragP, 0);
+-
+- gas_assert (xtensa_opcode_is_loop (isa, loop_insn.opcode) == 1);
+- addi_offset += loop_offset;
+- addmi_offset += loop_offset;
+-
+- gas_assert (tinsn->ntok == 2);
+- if (tinsn->tok[1].X_op == O_constant)
+- target = tinsn->tok[1].X_add_number;
+- else if (tinsn->tok[1].X_op == O_symbol)
+- {
+- /* Find the fragment. */
+- symbolS *sym = tinsn->tok[1].X_add_symbol;
+- gas_assert (S_GET_SEGMENT (sym) == segP
+- || S_GET_SEGMENT (sym) == absolute_section);
+- target = (S_GET_VALUE (sym) + tinsn->tok[1].X_add_number);
+- }
+- else
+- {
+- as_bad (_("invalid expression evaluation type %d"), tinsn->tok[1].X_op);
+- target = 0;
+- }
+-
+- loop_length = target - (fragP->fr_address + fragP->fr_fix);
+- loop_length_hi = loop_length & ~0x0ff;
+- loop_length_lo = loop_length & 0x0ff;
+- if (loop_length_lo >= 128)
+- {
+- loop_length_lo -= 256;
+- loop_length_hi += 256;
+- }
+-
+- /* Because addmi sign-extends the immediate, 'loop_length_hi' can be at most
+- 32512. If the loop is larger than that, then we just fail. */
+- if (loop_length_hi > 32512)
+- as_bad_where (fragP->fr_file, fragP->fr_line,
+- _("loop too long for LOOP instruction"));
+-
+- tinsn_from_chars (&addi_insn, fragP->fr_opcode + addi_offset, 0);
+- gas_assert (addi_insn.opcode == xtensa_addi_opcode);
+-
+- tinsn_from_chars (&addmi_insn, fragP->fr_opcode + addmi_offset, 0);
+- gas_assert (addmi_insn.opcode == xtensa_addmi_opcode);
+-
+- set_expr_const (&addi_insn.tok[2], loop_length_lo);
+- tinsn_to_insnbuf (&addi_insn, insnbuf);
+-
+- fragP->tc_frag_data.is_insn = TRUE;
+- xtensa_insnbuf_to_chars
+- (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addi_offset, 0);
+-
+- set_expr_const (&addmi_insn.tok[2], loop_length_hi);
+- tinsn_to_insnbuf (&addmi_insn, insnbuf);
+- xtensa_insnbuf_to_chars
+- (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addmi_offset, 0);
+-
+- /* Walk through all of the frags from here to the loop end
+- and mark them as no_transform to keep them from being modified
+- by the linker. If we ever have a relocation for the
+- addi/addmi of the difference of two symbols we can remove this. */
+-
+- target_count = 0;
+- for (next_fragP = fragP; next_fragP != NULL;
+- next_fragP = next_fragP->fr_next)
+- {
+- next_fragP->tc_frag_data.is_no_transform = TRUE;
+- if (next_fragP->tc_frag_data.is_loop_target)
+- target_count++;
+- if (target_count == 2)
+- break;
+- }
+-}
+-
+ \f
+ /* A map that keeps information on a per-subsegment basis. This is
+ maintained during initial assembly, but is invalid once the
+diff --git a/gas/config/xtensa-relax.c b/gas/config/xtensa-relax.c
+index cb296ed85ed2..daf15d52c259 100644
+--- a/gas/config/xtensa-relax.c
++++ b/gas/config/xtensa-relax.c
+@@ -87,13 +87,7 @@
+ when the first and second operands are not the same as specified
+ by the "| %at!=%as" precondition clause.
+ {"l32i %at,%as,%imm | %at!=%as",
+- "LITERAL %imm; l32r %at,%LITERAL; add %at,%at,%as; l32i %at,%at,0"}
+-
+- There is special case for loop instructions here, but because we do
+- not currently have the ability to represent the difference of two
+- symbols, the conversion requires special code in the assembler to
+- write the operands of the addi/addmi pair representing the
+- difference of the old and new loop end label. */
++ "LITERAL %imm; l32r %at,%LITERAL; add %at,%at,%as; l32i %at,%at,0"} */
+
+ #include "as.h"
+ #include "xtensa-isa.h"
+@@ -306,44 +300,83 @@ static string_pattern_pair widen_spec_list[] =
+ {"l32i %at,%as,%imm | %at!=%as ? IsaUseConst16",
+ "const16 %at,HI16U(%imm); const16 %at,LOW16U(%imm); add %at,%at,%as; l32i %at,%at,0"},
+
+- /* This is only PART of the loop instruction. In addition,
+- hardcoded into its use is a modification of the final operand in
+- the instruction in bytes 9 and 12. */
+- {"loop %as,%label | %as!=1 ? IsaUseLoops",
++ /* Widening loops with literals. */
++ {"loop %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "loop %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++ {"loopgtz %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "beqz %as,%label;"
++ "bltz %as,%label;"
++ "loopgtz %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++ {"loopnez %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "beqz %as,%label;"
++ "loopnez %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++
++ /* Widening loops with const16. */
++ {"loop %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "loop %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+- {"loopgtz %as,%label | %as!=1 ? IsaUseLoops",
++ {"loopgtz %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "beqz %as,%label;"
+ "bltz %as,%label;"
+ "loopgtz %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+- {"loopnez %as,%label | %as!=1 ? IsaUseLoops",
++ {"loopnez %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "beqz %as,%label;"
+ "loopnez %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+
+ /* Relaxing to wide branches. Order is important here. With wide
+--
+2.11.0
+
--- /dev/null
+From 0dbdfb7918d0b0cfcb8883b24c1291574bf5bb7c Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Tue, 2 Apr 2019 14:32:42 -0700
+Subject: [PATCH] gas: use literals/const16 for xtensa loop relaxation
+
+Loop opcode relaxation that uses addi/addmi doesn't work well with other
+relaxations that may cause code movement. Instead of encoding fixed loop
+end offset in the relaxed sequence use l32r or a pair of const16 to load
+loop end address. This way the address of the loop end gets a relocation
+record and it gets updated appropriately.
+
+gas/
+2019-04-02 Max Filippov <jcmvbkbc@gmail.com>
+
+ * config/tc-xtensa.c (convert_frag_immed): Drop
+ convert_frag_immed_finish_loop invocation.
+ (convert_frag_immed_finish_loop): Drop declaration and
+ definition.
+ * config/xtensa-relax.c (widen_spec_list): Replace loop
+ widening that uses addi/addmi with widening that uses l32r
+ and const16.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+ gas/config/tc-xtensa.c | 120 ----------------------------------------------
+ gas/config/xtensa-relax.c | 77 ++++++++++++++++++++---------
+ 2 files changed, 55 insertions(+), 142 deletions(-)
+
+diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
+index 3bdbbc931cfc..0cc06361cf6f 100644
+--- a/gas/config/tc-xtensa.c
++++ b/gas/config/tc-xtensa.c
+@@ -10668,7 +10668,6 @@ convert_frag_fill_nop (fragS *fragP)
+ static fixS *fix_new_exp_in_seg
+ (segT, subsegT, fragS *, int, int, expressionS *, int,
+ bfd_reloc_code_real_type);
+-static void convert_frag_immed_finish_loop (segT, fragS *, TInsn *);
+
+ static void
+ convert_frag_immed (segT segP,
+@@ -10910,9 +10909,6 @@ convert_frag_immed (segT segP,
+ }
+ }
+
+- if (expanded && xtensa_opcode_is_loop (isa, orig_tinsn.opcode) == 1)
+- convert_frag_immed_finish_loop (segP, fragP, &orig_tinsn);
+-
+ if (expanded && is_direct_call_opcode (orig_tinsn.opcode))
+ {
+ /* Add an expansion note on the expanded instruction. */
+@@ -10949,122 +10945,6 @@ fix_new_exp_in_seg (segT new_seg,
+ }
+
+
+-/* Relax a loop instruction so that it can span loop >256 bytes.
+-
+- loop as, .L1
+- .L0:
+- rsr as, LEND
+- wsr as, LBEG
+- addi as, as, lo8 (label-.L1)
+- addmi as, as, mid8 (label-.L1)
+- wsr as, LEND
+- isync
+- rsr as, LCOUNT
+- addi as, as, 1
+- .L1:
+- <<body>>
+- label:
+-*/
+-
+-static void
+-convert_frag_immed_finish_loop (segT segP, fragS *fragP, TInsn *tinsn)
+-{
+- TInsn loop_insn;
+- TInsn addi_insn;
+- TInsn addmi_insn;
+- unsigned long target;
+- static xtensa_insnbuf insnbuf = NULL;
+- unsigned int loop_length, loop_length_hi, loop_length_lo;
+- xtensa_isa isa = xtensa_default_isa;
+- addressT loop_offset;
+- addressT addi_offset = 9;
+- addressT addmi_offset = 12;
+- fragS *next_fragP;
+- int target_count;
+-
+- if (!insnbuf)
+- insnbuf = xtensa_insnbuf_alloc (isa);
+-
+- /* Get the loop offset. */
+- loop_offset = get_expanded_loop_offset (tinsn->opcode);
+-
+- /* Validate that there really is a LOOP at the loop_offset. Because
+- loops are not bundleable, we can assume that the instruction will be
+- in slot 0. */
+- tinsn_from_chars (&loop_insn, fragP->fr_opcode + loop_offset, 0);
+- tinsn_immed_from_frag (&loop_insn, fragP, 0);
+-
+- gas_assert (xtensa_opcode_is_loop (isa, loop_insn.opcode) == 1);
+- addi_offset += loop_offset;
+- addmi_offset += loop_offset;
+-
+- gas_assert (tinsn->ntok == 2);
+- if (tinsn->tok[1].X_op == O_constant)
+- target = tinsn->tok[1].X_add_number;
+- else if (tinsn->tok[1].X_op == O_symbol)
+- {
+- /* Find the fragment. */
+- symbolS *sym = tinsn->tok[1].X_add_symbol;
+- gas_assert (S_GET_SEGMENT (sym) == segP
+- || S_GET_SEGMENT (sym) == absolute_section);
+- target = (S_GET_VALUE (sym) + tinsn->tok[1].X_add_number);
+- }
+- else
+- {
+- as_bad (_("invalid expression evaluation type %d"), tinsn->tok[1].X_op);
+- target = 0;
+- }
+-
+- loop_length = target - (fragP->fr_address + fragP->fr_fix);
+- loop_length_hi = loop_length & ~0x0ff;
+- loop_length_lo = loop_length & 0x0ff;
+- if (loop_length_lo >= 128)
+- {
+- loop_length_lo -= 256;
+- loop_length_hi += 256;
+- }
+-
+- /* Because addmi sign-extends the immediate, 'loop_length_hi' can be at most
+- 32512. If the loop is larger than that, then we just fail. */
+- if (loop_length_hi > 32512)
+- as_bad_where (fragP->fr_file, fragP->fr_line,
+- _("loop too long for LOOP instruction"));
+-
+- tinsn_from_chars (&addi_insn, fragP->fr_opcode + addi_offset, 0);
+- gas_assert (addi_insn.opcode == xtensa_addi_opcode);
+-
+- tinsn_from_chars (&addmi_insn, fragP->fr_opcode + addmi_offset, 0);
+- gas_assert (addmi_insn.opcode == xtensa_addmi_opcode);
+-
+- set_expr_const (&addi_insn.tok[2], loop_length_lo);
+- tinsn_to_insnbuf (&addi_insn, insnbuf);
+-
+- fragP->tc_frag_data.is_insn = TRUE;
+- xtensa_insnbuf_to_chars
+- (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addi_offset, 0);
+-
+- set_expr_const (&addmi_insn.tok[2], loop_length_hi);
+- tinsn_to_insnbuf (&addmi_insn, insnbuf);
+- xtensa_insnbuf_to_chars
+- (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addmi_offset, 0);
+-
+- /* Walk through all of the frags from here to the loop end
+- and mark them as no_transform to keep them from being modified
+- by the linker. If we ever have a relocation for the
+- addi/addmi of the difference of two symbols we can remove this. */
+-
+- target_count = 0;
+- for (next_fragP = fragP; next_fragP != NULL;
+- next_fragP = next_fragP->fr_next)
+- {
+- next_fragP->tc_frag_data.is_no_transform = TRUE;
+- if (next_fragP->tc_frag_data.is_loop_target)
+- target_count++;
+- if (target_count == 2)
+- break;
+- }
+-}
+-
+ \f
+ /* A map that keeps information on a per-subsegment basis. This is
+ maintained during initial assembly, but is invalid once the
+diff --git a/gas/config/xtensa-relax.c b/gas/config/xtensa-relax.c
+index cb296ed85ed2..daf15d52c259 100644
+--- a/gas/config/xtensa-relax.c
++++ b/gas/config/xtensa-relax.c
+@@ -87,13 +87,7 @@
+ when the first and second operands are not the same as specified
+ by the "| %at!=%as" precondition clause.
+ {"l32i %at,%as,%imm | %at!=%as",
+- "LITERAL %imm; l32r %at,%LITERAL; add %at,%at,%as; l32i %at,%at,0"}
+-
+- There is special case for loop instructions here, but because we do
+- not currently have the ability to represent the difference of two
+- symbols, the conversion requires special code in the assembler to
+- write the operands of the addi/addmi pair representing the
+- difference of the old and new loop end label. */
++ "LITERAL %imm; l32r %at,%LITERAL; add %at,%at,%as; l32i %at,%at,0"} */
+
+ #include "as.h"
+ #include "xtensa-isa.h"
+@@ -306,44 +300,83 @@ static string_pattern_pair widen_spec_list[] =
+ {"l32i %at,%as,%imm | %at!=%as ? IsaUseConst16",
+ "const16 %at,HI16U(%imm); const16 %at,LOW16U(%imm); add %at,%at,%as; l32i %at,%at,0"},
+
+- /* This is only PART of the loop instruction. In addition,
+- hardcoded into its use is a modification of the final operand in
+- the instruction in bytes 9 and 12. */
+- {"loop %as,%label | %as!=1 ? IsaUseLoops",
++ /* Widening loops with literals. */
++ {"loop %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "loop %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++ {"loopgtz %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "beqz %as,%label;"
++ "bltz %as,%label;"
++ "loopgtz %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++ {"loopnez %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "beqz %as,%label;"
++ "loopnez %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++
++ /* Widening loops with const16. */
++ {"loop %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "loop %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+- {"loopgtz %as,%label | %as!=1 ? IsaUseLoops",
++ {"loopgtz %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "beqz %as,%label;"
+ "bltz %as,%label;"
+ "loopgtz %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+- {"loopnez %as,%label | %as!=1 ? IsaUseLoops",
++ {"loopnez %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "beqz %as,%label;"
+ "loopnez %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+
+ /* Relaxing to wide branches. Order is important here. With wide
+--
+2.11.0
+
--- /dev/null
+From 0dbdfb7918d0b0cfcb8883b24c1291574bf5bb7c Mon Sep 17 00:00:00 2001
+From: Max Filippov <jcmvbkbc@gmail.com>
+Date: Tue, 2 Apr 2019 14:32:42 -0700
+Subject: [PATCH] gas: use literals/const16 for xtensa loop relaxation
+
+Loop opcode relaxation that uses addi/addmi doesn't work well with other
+relaxations that may cause code movement. Instead of encoding fixed loop
+end offset in the relaxed sequence use l32r or a pair of const16 to load
+loop end address. This way the address of the loop end gets a relocation
+record and it gets updated appropriately.
+
+gas/
+2019-04-02 Max Filippov <jcmvbkbc@gmail.com>
+
+ * config/tc-xtensa.c (convert_frag_immed): Drop
+ convert_frag_immed_finish_loop invocation.
+ (convert_frag_immed_finish_loop): Drop declaration and
+ definition.
+ * config/xtensa-relax.c (widen_spec_list): Replace loop
+ widening that uses addi/addmi with widening that uses l32r
+ and const16.
+
+Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
+---
+ gas/config/tc-xtensa.c | 120 ----------------------------------------------
+ gas/config/xtensa-relax.c | 77 ++++++++++++++++++++---------
+ 2 files changed, 55 insertions(+), 142 deletions(-)
+
+diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c
+index 3bdbbc931cfc..0cc06361cf6f 100644
+--- a/gas/config/tc-xtensa.c
++++ b/gas/config/tc-xtensa.c
+@@ -10668,7 +10668,6 @@ convert_frag_fill_nop (fragS *fragP)
+ static fixS *fix_new_exp_in_seg
+ (segT, subsegT, fragS *, int, int, expressionS *, int,
+ bfd_reloc_code_real_type);
+-static void convert_frag_immed_finish_loop (segT, fragS *, TInsn *);
+
+ static void
+ convert_frag_immed (segT segP,
+@@ -10910,9 +10909,6 @@ convert_frag_immed (segT segP,
+ }
+ }
+
+- if (expanded && xtensa_opcode_is_loop (isa, orig_tinsn.opcode) == 1)
+- convert_frag_immed_finish_loop (segP, fragP, &orig_tinsn);
+-
+ if (expanded && is_direct_call_opcode (orig_tinsn.opcode))
+ {
+ /* Add an expansion note on the expanded instruction. */
+@@ -10949,122 +10945,6 @@ fix_new_exp_in_seg (segT new_seg,
+ }
+
+
+-/* Relax a loop instruction so that it can span loop >256 bytes.
+-
+- loop as, .L1
+- .L0:
+- rsr as, LEND
+- wsr as, LBEG
+- addi as, as, lo8 (label-.L1)
+- addmi as, as, mid8 (label-.L1)
+- wsr as, LEND
+- isync
+- rsr as, LCOUNT
+- addi as, as, 1
+- .L1:
+- <<body>>
+- label:
+-*/
+-
+-static void
+-convert_frag_immed_finish_loop (segT segP, fragS *fragP, TInsn *tinsn)
+-{
+- TInsn loop_insn;
+- TInsn addi_insn;
+- TInsn addmi_insn;
+- unsigned long target;
+- static xtensa_insnbuf insnbuf = NULL;
+- unsigned int loop_length, loop_length_hi, loop_length_lo;
+- xtensa_isa isa = xtensa_default_isa;
+- addressT loop_offset;
+- addressT addi_offset = 9;
+- addressT addmi_offset = 12;
+- fragS *next_fragP;
+- int target_count;
+-
+- if (!insnbuf)
+- insnbuf = xtensa_insnbuf_alloc (isa);
+-
+- /* Get the loop offset. */
+- loop_offset = get_expanded_loop_offset (tinsn->opcode);
+-
+- /* Validate that there really is a LOOP at the loop_offset. Because
+- loops are not bundleable, we can assume that the instruction will be
+- in slot 0. */
+- tinsn_from_chars (&loop_insn, fragP->fr_opcode + loop_offset, 0);
+- tinsn_immed_from_frag (&loop_insn, fragP, 0);
+-
+- gas_assert (xtensa_opcode_is_loop (isa, loop_insn.opcode) == 1);
+- addi_offset += loop_offset;
+- addmi_offset += loop_offset;
+-
+- gas_assert (tinsn->ntok == 2);
+- if (tinsn->tok[1].X_op == O_constant)
+- target = tinsn->tok[1].X_add_number;
+- else if (tinsn->tok[1].X_op == O_symbol)
+- {
+- /* Find the fragment. */
+- symbolS *sym = tinsn->tok[1].X_add_symbol;
+- gas_assert (S_GET_SEGMENT (sym) == segP
+- || S_GET_SEGMENT (sym) == absolute_section);
+- target = (S_GET_VALUE (sym) + tinsn->tok[1].X_add_number);
+- }
+- else
+- {
+- as_bad (_("invalid expression evaluation type %d"), tinsn->tok[1].X_op);
+- target = 0;
+- }
+-
+- loop_length = target - (fragP->fr_address + fragP->fr_fix);
+- loop_length_hi = loop_length & ~0x0ff;
+- loop_length_lo = loop_length & 0x0ff;
+- if (loop_length_lo >= 128)
+- {
+- loop_length_lo -= 256;
+- loop_length_hi += 256;
+- }
+-
+- /* Because addmi sign-extends the immediate, 'loop_length_hi' can be at most
+- 32512. If the loop is larger than that, then we just fail. */
+- if (loop_length_hi > 32512)
+- as_bad_where (fragP->fr_file, fragP->fr_line,
+- _("loop too long for LOOP instruction"));
+-
+- tinsn_from_chars (&addi_insn, fragP->fr_opcode + addi_offset, 0);
+- gas_assert (addi_insn.opcode == xtensa_addi_opcode);
+-
+- tinsn_from_chars (&addmi_insn, fragP->fr_opcode + addmi_offset, 0);
+- gas_assert (addmi_insn.opcode == xtensa_addmi_opcode);
+-
+- set_expr_const (&addi_insn.tok[2], loop_length_lo);
+- tinsn_to_insnbuf (&addi_insn, insnbuf);
+-
+- fragP->tc_frag_data.is_insn = TRUE;
+- xtensa_insnbuf_to_chars
+- (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addi_offset, 0);
+-
+- set_expr_const (&addmi_insn.tok[2], loop_length_hi);
+- tinsn_to_insnbuf (&addmi_insn, insnbuf);
+- xtensa_insnbuf_to_chars
+- (isa, insnbuf, (unsigned char *) fragP->fr_opcode + addmi_offset, 0);
+-
+- /* Walk through all of the frags from here to the loop end
+- and mark them as no_transform to keep them from being modified
+- by the linker. If we ever have a relocation for the
+- addi/addmi of the difference of two symbols we can remove this. */
+-
+- target_count = 0;
+- for (next_fragP = fragP; next_fragP != NULL;
+- next_fragP = next_fragP->fr_next)
+- {
+- next_fragP->tc_frag_data.is_no_transform = TRUE;
+- if (next_fragP->tc_frag_data.is_loop_target)
+- target_count++;
+- if (target_count == 2)
+- break;
+- }
+-}
+-
+ \f
+ /* A map that keeps information on a per-subsegment basis. This is
+ maintained during initial assembly, but is invalid once the
+diff --git a/gas/config/xtensa-relax.c b/gas/config/xtensa-relax.c
+index cb296ed85ed2..daf15d52c259 100644
+--- a/gas/config/xtensa-relax.c
++++ b/gas/config/xtensa-relax.c
+@@ -87,13 +87,7 @@
+ when the first and second operands are not the same as specified
+ by the "| %at!=%as" precondition clause.
+ {"l32i %at,%as,%imm | %at!=%as",
+- "LITERAL %imm; l32r %at,%LITERAL; add %at,%at,%as; l32i %at,%at,0"}
+-
+- There is special case for loop instructions here, but because we do
+- not currently have the ability to represent the difference of two
+- symbols, the conversion requires special code in the assembler to
+- write the operands of the addi/addmi pair representing the
+- difference of the old and new loop end label. */
++ "LITERAL %imm; l32r %at,%LITERAL; add %at,%at,%as; l32i %at,%at,0"} */
+
+ #include "as.h"
+ #include "xtensa-isa.h"
+@@ -306,44 +300,83 @@ static string_pattern_pair widen_spec_list[] =
+ {"l32i %at,%as,%imm | %at!=%as ? IsaUseConst16",
+ "const16 %at,HI16U(%imm); const16 %at,LOW16U(%imm); add %at,%at,%as; l32i %at,%at,0"},
+
+- /* This is only PART of the loop instruction. In addition,
+- hardcoded into its use is a modification of the final operand in
+- the instruction in bytes 9 and 12. */
+- {"loop %as,%label | %as!=1 ? IsaUseLoops",
++ /* Widening loops with literals. */
++ {"loop %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "loop %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++ {"loopgtz %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "beqz %as,%label;"
++ "bltz %as,%label;"
++ "loopgtz %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++ {"loopnez %as,%label | %as!=1 ? IsaUseLoops ? IsaUseL32R",
++ "beqz %as,%label;"
++ "loopnez %as,%LABEL;"
++ "rsr.lend %as;" /* LEND */
++ "wsr.lbeg %as;" /* LBEG */
++ "LITERAL %label;"
++ "l32r %as, %LITERAL;"
++ "nop;"
++ "wsr.lend %as;"
++ "isync;"
++ "rsr.lcount %as;" /* LCOUNT */
++ "addi %as, %as, 1;"
++ "LABEL"},
++
++ /* Widening loops with const16. */
++ {"loop %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "loop %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+- {"loopgtz %as,%label | %as!=1 ? IsaUseLoops",
++ {"loopgtz %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "beqz %as,%label;"
+ "bltz %as,%label;"
+ "loopgtz %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+- {"loopnez %as,%label | %as!=1 ? IsaUseLoops",
++ {"loopnez %as,%label | %as!=1 ? IsaUseLoops ? IsaUseConst16",
+ "beqz %as,%label;"
+ "loopnez %as,%LABEL;"
+ "rsr.lend %as;" /* LEND */
+ "wsr.lbeg %as;" /* LBEG */
+- "addi %as, %as, 0;" /* lo8(%label-%LABEL1) */
+- "addmi %as, %as, 0;" /* mid8(%label-%LABEL1) */
++ "const16 %as,HI16U(%label);"
++ "const16 %as,LOW16U(%label);"
+ "wsr.lend %as;"
+ "isync;"
+ "rsr.lcount %as;" /* LCOUNT */
+- "addi %as, %as, 1;" /* density -> addi.n %as, %as, 1 */
++ "addi %as, %as, 1;"
+ "LABEL"},
+
+ /* Relaxing to wide branches. Order is important here. With wide
+--
+2.11.0
+
projects / buildroot.git / commitdiff