Adding memory write to a sparc fsqrts insn
Hello everybody, I'd like to patch gcc's sparc machine descritpion so that the destination register of a fpu sqareroot operation fsqrts is stored into memory after each fsqrts. like this: fsqrts %f2,%f4 st %f4, -4[%fp] <= add this after every fsqrts where -4[%fp] is a slot allocated on the stack for each fsqrts insn The sparc.md portion that defines the fsqrts pattern is: (define_insn "sqrtsf2" [(set (match_operand:SF 0 "register_operand" "=f") (sqrt:SF (match_operand:SF 1 "register_operand" "f")))] "TARGET_FPU" "fsqrts\t%1, %0" [(set_attr "type" "fpsqrts")]) i thought I could add the "st %f4, -4[%fp]" there. But now my question: - Where/when/how can I allocate the stackframe slot to save the destination fp reg in (the offset to %fp). I'm not that familiar with rtl representation and the stages of compilation. So any help would be apreciated. Maybe another architecture has a similar construct already that I could study and use for my purpose. If somebody can point me to such machine description part ... -- Greetings Konrad
Generating store after fdivd: how to avoid delay slot
I try to patch gcc so that after a fdivd the destination register is
stored to the stack.
fdivd %f0,%f2,%f4; std %f4, [%sp]
I generate the rtl for divdf3 using a emit_insn,DONE sequence in a
define_expand pattern (see below).
In the assembler output phase I use a define_insn and write
out "fdivd\t%%1, %%2, %%0; std %%0, %%3" as the expression string.
My question:
- How can I mark the pattern so that it will not be sheduled into a
delay slot? How can I specify that the output will be 2 instructions
and hint the scheduler about it?
- Is the (set_attr "length" "2") attribute in define_insn divdf3_store
(below) already sufficient?
-- Greetings Konrad
;; handle divdf3
(define_expand "divdf3"
[(parallel [(set (match_operand:DF 0 "register_operand" "=e")
(div:DF (match_operand:DF 1 "register_operand" "e")
(match_operand:DF 2 "register_operand" "e")))
(clobber (match_scratch:SI 3 ""))])]
"TARGET_FPU"
"{
output_divdf3_emit (operands[0], operands[1], operands[2], operands[3]);
DONE;
}")
(define_insn "divdf3_store"
[(set (match_operand:DF 0 "register_operand" "=e")
(div:DF (match_operand:DF 1 "register_operand" "e")
(match_operand:DF 2 "register_operand" "e")))
(clobber (match_operand:DF 3 "memory_operand" "" ))]
"TARGET_FPU && TARGET_STORE_AFTER_DIVSQRT"
{
return output_divdf3 (operands[0], operands[1], operands[2],
operands[3]);
}
[(set_attr "type" "fpdivd")
(set_attr "fptype" "double")
(set_attr "length" "2")])
(define_insn "divdf3_nostore"
[(set (match_operand:DF 0 "register_operand" "=e")
(div:DF (match_operand:DF 1 "register_operand" "e")
(match_operand:DF 2 "register_operand" "e")))]
"TARGET_FPU && (!TARGET_STORE_AFTER_DIVSQRT)"
"fdivd\t%1, %2, %0"
[(set_attr "type" "fpdivd")
(set_attr "fptype" "double")])
/ handle fdivd /
char *
output_divdf3 (rtx op0, rtx op1, rtx dest, rtx scratch)
{
static char string[128];
sprintf(string,"fdivd\t%%1, %%2, %%0; std %%0, %%3 !!!");
return string;
}
void
output_divdf3_emit (rtx dest, rtx op0, rtx op1, rtx scratch)
{
rtx slot0, div, divsave;
div = gen_rtx_SET (VOIDmode,
dest,
gen_rtx_DIV (DFmode,
op0,
op1));
if (TARGET_STORE_AFTER_DIVSQRT) {
slot0 = assign_stack_local (DFmode, 8, 8);
divsave = gen_rtx_SET (VOIDmode, slot0, dest);
emit_insn(divsave);
emit_insn (gen_rtx_PARALLEL(VOIDmode,
gen_rtvec (2,
div,
gen_rtx_CLOBBER (SImode,
slot0;
} else {
emit_insn(div);
}
}
Automatic cast off "union tree" in gdb
Hi, When stepping through gcc with gdb: is there a way to be able to make gdb automatically cast a "union tree" to the correct struct depending on the union tree's type? A "p " will print out all unions. I'd not want to do a cast all the time. -- Konrad
Re: GCC 7.5 Released
'''bauernkönigin''' 2019-11-14 10:01 GMT+01:00, Richard Biener : > > The GNU Compiler Collection version 7.5 has been released. > > GCC 7.5 is a bug-fix release from the GCC 7 branch > containing important fixes for regressions and serious bugs in > GCC 7.4 with more than 215 bugs fixed since the previous release. > > This is also the last release from the GCC 7 branch which will receive > no further fixes from now on. GCC continues to be maintained on > the GCC 8 and GCC 9 branches and the development trunk. > > This release is available from the FTP servers listed at: > > http://www.gnu.org/order/ftp.html > > Please do not contact me directly regarding questions or comments > about this release. Instead, use the resources available from > http://gcc.gnu.org. > > As always, a vast number of people contributed to this GCC release > -- far too many to thank them individually! > -- OrG value? fuck.classList 1 Ostpreußen-russe-Gakushūjo capraso FE-College Darth Vader () ; (i) (i) 0 iOS 3 @RSS codeproject.com _TZ _tz Firefox OS 1 FFOS Fxos ; USt-IdNr.: DE325658490
