https://gcc.gnu.org/g:7f04fddec3bc33b6fb418f3980995b9b7697e6b1
commit r12-10827-g7f04fddec3bc33b6fb418f3980995b9b7697e6b1
Author: Georg-Johann Lay <a...@gjlay.de>
Date: Sat Nov 23 12:51:32 2024 +0100
AVR: target/117744 - Fix asm for partial clobber of address reg,
gcc/
PR target/117744
* config/avr/avr.cc (out_movqi_r_mr): Fix code when a load
only partially clobbers an address register due to
changing the address register temporally to accommodate for
faked addressing modes.
(cherry picked from commit ee8e6784876aa050d2e01f54d1da4acf758b635a)
Diff:
---
gcc/config/avr/avr.cc | 76 ++++++++++++++++++++++++++++++++++-----------------
1 file changed, 51 insertions(+), 25 deletions(-)
diff --git a/gcc/config/avr/avr.cc b/gcc/config/avr/avr.cc
index c0f5242c0b2e..5d63c7153d6e 100644
--- a/gcc/config/avr/avr.cc
+++ b/gcc/config/avr/avr.cc
@@ -4241,11 +4241,11 @@ avr_out_movqi_r_mr_reg_disp_tiny (rtx_insn *insn, rtx
op[], int *plen)
rtx base2 = all_regs_rtx[1 ^ REGNO (dest)];
if (!reg_unused_after (insn, base2))
- avr_asm_len ("mov __tmp_reg__,%0" , &base2, plen, 1);
+ avr_asm_len ("mov __tmp_reg__,%0", &base2, plen, 1);
avr_asm_len (TINY_ADIW (%I1, %J1, %o1) CR_TAB
"ld %0,%b1", op, plen, 3);
if (!reg_unused_after (insn, base2))
- avr_asm_len ("mov %0,__tmp_reg__" , &base2, plen, 1);
+ avr_asm_len ("mov %0,__tmp_reg__", &base2, plen, 1);
}
return "";
@@ -4272,40 +4272,66 @@ out_movqi_r_mr (rtx_insn *insn, rtx op[], int *plen)
{
/* memory access by reg+disp */
- int disp = INTVAL (XEXP (x, 1));
-
if (AVR_TINY)
return avr_out_movqi_r_mr_reg_disp_tiny (insn, op, plen);
+ if (plen)
+ *plen = 0;
+
+ int disp = INTVAL (XEXP (x, 1));
+ rtx base = XEXP (x, 0);
+ rtx base2 = all_regs_rtx[1 ^ REGNO (dest)];
+ bool partial_clobber = (reg_overlap_mentioned_p (dest, base)
+ && ! reg_unused_after (insn, base2));
+
if (disp - GET_MODE_SIZE (GET_MODE (src)) >= 63)
- {
- if (REGNO (XEXP (x, 0)) != REG_Y)
- fatal_insn ("incorrect insn:",insn);
+ {
+ // PR117744: The base register overlaps dest and is
+ // only partially clobbered.
+ if (partial_clobber)
+ avr_asm_len ("mov __tmp_reg__,%0", &base2, plen, 1);
- if (disp <= 63 + MAX_LD_OFFSET (GET_MODE (src)))
- return avr_asm_len ("adiw r28,%o1-63" CR_TAB
- "ldd %0,Y+63" CR_TAB
- "sbiw r28,%o1-63", op, plen, -3);
+ if (REGNO (XEXP (x, 0)) != REG_Y)
+ fatal_insn ("incorrect insn:",insn);
- return avr_asm_len ("subi r28,lo8(-%o1)" CR_TAB
- "sbci r29,hi8(-%o1)" CR_TAB
- "ld %0,Y" CR_TAB
- "subi r28,lo8(%o1)" CR_TAB
- "sbci r29,hi8(%o1)", op, plen, -5);
- }
+ if (disp <= 63 + MAX_LD_OFFSET (GET_MODE (src)))
+ avr_asm_len ("adiw r28,%o1-63" CR_TAB
+ "ldd %0,Y+63" CR_TAB
+ "sbiw r28,%o1-63", op, plen, 3);
+ else
+ avr_asm_len ("subi r28,lo8(-%o1)" CR_TAB
+ "sbci r29,hi8(-%o1)" CR_TAB
+ "ld %0,Y" CR_TAB
+ "subi r28,lo8(%o1)" CR_TAB
+ "sbci r29,hi8(%o1)", op, plen, 5);
+
+ if (partial_clobber)
+ avr_asm_len ("mov __tmp_reg__,%0", &base2, plen, 1);
+
+ return "";
+ }
else if (REGNO (XEXP (x, 0)) == REG_X)
{
/* This is a paranoid case LEGITIMIZE_RELOAD_ADDRESS must exclude
it but I have this situation with extremal optimizing options. */
- avr_asm_len ("adiw r26,%o1" CR_TAB
- "ld %0,X", op, plen, -2);
-
- if (!reg_overlap_mentioned_p (dest, XEXP (x, 0))
- && !reg_unused_after (insn, XEXP (x, 0)))
- {
- avr_asm_len ("sbiw r26,%o1", op, plen, 1);
- }
+ // PR117744: The base register overlaps dest and is
+ // only partially clobbered.
+ bool clobber_r26 = (partial_clobber
+ && REGNO (base) == (REGNO (base) & ~1));
+ if (partial_clobber
+ && ! clobber_r26)
+ avr_asm_len ("mov __tmp_reg__,%0", &base2, plen, 1);
+
+ avr_asm_len ("adiw r26,%o1" CR_TAB
+ "ld %0,X", op, plen, 2);
+
+ if (clobber_r26)
+ avr_asm_len ("subi r26,lo8(%o1)", op, plen, 1);
+ else if (partial_clobber)
+ avr_asm_len ("mov %0,__tmp_reg__", &base2, plen, 1);
+ else if (! reg_unused_after (insn, base))
+ avr_asm_len ("sbiw r26,%o1", op, plen, 1);
return "";
}
