On Wed, Mar 11, 2009 at 2:54 PM, Toon Moene <t...@moene.org> wrote:
> ... and it had to be "fixed" 3-4 times by H.J.Lu before it went so obscure
> to only hit people like me.
>
> I run a weather forecasting system 4 times daily to test it out.
>
> Because GCC would-be-4.4 is in regression fixes only during the last four
> months, I thought I could use it with impunity.
>
> Unfortunately, not so.
>
> From the 17th of February onwards, I find the following diagnostics in my
> output files:
>
> -------------------------------
> ABS(DPS)/3H = 1.007571 MB
> MAXWIND = 70.835266 M/S IN (X,Y,LEV)= 129 145 15
> STPS = 10077.023437500000
> STQ = 4.921556472778
> STS = 0.010799089447
> STPE = 2497269760.000000000000
> STKE = 1622026.375000000000
> STTE = 2498891776.000000000000
>
> TOTAL RAIN RATE(mm/d)= +Infinity
> STRATIFORM PRECIP RATE= +Infinity
> CONVECTIVE PRECIP RATE= 0.000000000000
> CWPATH = +Infinity
> COV2D = +Infinity
> HIGH CLOUDS = +Infinity
> MEDIUM CLOUDS = +Infinity
> LOW CLOUDS = +Infinity
> LOWEST LEVEL CLOUDS/FOG = +Infinity
> AVERAGED CLOUD BASE= +Infinity
> AVERAGED CLOUD TOP= +Infinity
> SENF = -Infinity
> LATF = NaN
> MOMF = +Infinity
>
> Without going into meteorological details, I hope you will trust me that the
> Infinity's, NaN's should not be there.
>
> After reverting r144098 and its updates today, the output looks normal:
>
> -------------------------------
> ABS(DPS)/3H = 1.144242 MB
> MAXWIND = 75.913940 M/S IN (X,Y,LEV)= 155 151 13
> STPS = 10076.395507812500
> STQ = 4.889474391937
> STS = 0.006965990644
> STPE = 2498901504.000000000000
> STKE = 1634238.125000000000
> STTE = 2500535808.000000000000
>
> TOTAL RAIN RATE(mm/d)= 0.150563895702
> STRATIFORM PRECIP RATE= 0.146368727088
> CONVECTIVE PRECIP RATE= 0.004195173737
> CWPATH = 0.009085088037
> COV2D = 0.115943998098
> HIGH CLOUDS = 0.052225619555
> MEDIUM CLOUDS = 0.031857494265
> LOW CLOUDS = 0.062132436782
> LOWEST LEVEL CLOUDS/FOG = 0.006665431429
> AVERAGED CLOUD BASE= 448.916229248047
> AVERAGED CLOUD TOP= 900.125244140625
> SENF = -30.753757476807
> LATF = -70.874824523926
> MOMF = 0.177236527205
>
> So *during phase 4 - regression fixes only* a change *introducing* two
> peephole optimizations was not only proposed, but accepted and committed
> (and "fixed", at least three times).
>
Does this look correct?
(define_peephole2
[(set (match_operand:SI 0 "register_operand" "")
(match_operand:SI 1 "register_operand" ""))
(parallel [(set (match_dup 0)
(match_operator:SI 3 "commutative_operator"
[(match_dup 0)
(match_operand:SI 2 "memory_operand" "")]))
(clobber (reg:CC FLAGS_REG))])]
"operands[0] != operands[1]
&& GENERAL_REGNO_P (REGNO (operands[0]))
&& GENERAL_REGNO_P (REGNO (operands[1]))"
[(set (match_dup 0) (match_dup 4))
(parallel [(set (match_dup 0)
(match_op_dup 3 [(match_dup 0) (match_dup 1)]))
(clobber (reg:CC FLAGS_REG))])]
"operands[4] = replace_rtx (operands[2], operands[0], operands[1]);")
If operands[2] uses operands[0], we replace it with operands[1]. It leads
to
(set (match_dup 0) (match_dup 4))
where (match_dup 4) uses operands[1] which may be uninitialized.
Shouldn't it be
"operands[4] = replace_rtx (operands[2], operands[1], operands[0]);")
Did I miss something?
--
H.J.
