`-fno-state-hack` produces incorrect results in nofib

While investigating #7411, I found that nofib fails with incorrect output from the fasta test.

A vanilla prof build behaves normally; however, with the following modifications, nofib fails:

• Compile GHC from scratch with:

GhcStage2HcOpts = -O -fno-state-hack GhcLibHcOpts = -O -fno-state-hack

• Run nofib with EXTRA_HC_OPTS=-fno-state-hack

Doing this, the nofib test output is:

------------------------------------------------------------------------
== make all --no-print-directory;
 in /home/tobias/well-typed/devel/ghc/HEAD/nofib/shootout/fasta
------------------------------------------------------------------------
HC = /home/tobias/well-typed/devel/ghc/HEAD/inplace/bin/ghc-stage2
HC_OPTS = -O2 -Rghc-timing -H32m -hisuf hi -fno-state-hack -O2 -rtsopts -O2 -XBangPatterns -XOverloadedStrings -package bytestring
RUNTEST_OPTS = -ghc-timing
==nofib== fasta: time to compile Main follows...
/home/tobias/well-typed/devel/ghc/HEAD/inplace/bin/ghc-stage2 -O2 -Rghc-timing -H32m -hisuf hi -fno-state-hack -O2 -rtsopts -O2 -XBangPatterns -XOverloadedStrings -package bytestring -c Main.hs -o Main.o

Main.hs:30:1: warning: [-Wtabs]
    Tab character found here, and in 13 further locations.
    Please use spaces instead.
   |
30 |         let !k = min modulus (floor (fromIntegral modulus * (p::Float) + 1))
   | ^^^^^^^^
<<ghc: 401958512 bytes, 72 GCs, 10720054/28796976 avg/max bytes residency (6 samples), 61M in use, 0.001 INIT (0.001 elapsed), 0.342 MUT (0.420 elapsed), 0.240 GC (0.238 elapsed) :ghc>>
==nofib== fasta: size of Main.o follows...
   text	   data	    bss	    dec	    hex	filename
   7245	   2624	      0	   9869	   268d	Main.o
==nofib== fasta: time to link fasta follows...
<<ghc: 49626024 bytes, 45 GCs, 1356153/2672728 avg/max bytes residency (5 samples), 8M in use, 0.001 INIT (0.001 elapsed), 0.025 MUT (0.468 elapsed), 0.060 GC (0.060 elapsed) :ghc>>
==nofib== fasta: size of fasta follows...
   text	   data	    bss	    dec	    hex	filename
 708996	 127712	  16232	 852940	  d03cc	fasta
==nofib== fasta: time to run fasta follows...
../../runstdtest/runstdtest ./fasta  -o1 fasta.stdout -o1 fasta.stdout  -ghc-timing     2500000;   ../../runstdtest/runstdtest ./fasta  -o1 fasta.stdout -o1 fasta.stdout  -ghc-timing     2500000;   ../../runstdtest/runstdtest ./fasta  -o1 fasta.stdout -o1 fasta.stdout  -ghc-timing     2500000;   ../../runstdtest/runstdtest ./fasta  -o1 fasta.stdout -o1 fasta.stdout  -ghc-timing     2500000;   ../../runstdtest/runstdtest ./fasta  -o1 fasta.stdout -o1 fasta.stdout  -ghc-timing     2500000;
0.43user 0.02system 0:00.45elapsed 99%CPU (0avgtext+0avgdata 4824maxresident)k
0inputs+49656outputs (0major+608minor)pagefaults 0swaps
././fasta 2500000 < /dev/null
expected stdout not matched by reality
--- fasta.stdout	2018-06-02 03:00:43.887025433 +0200
+++ /tmp/runtest4673.1	2018-06-02 03:09:19.651755697 +0200
@@ -83337,333335 +83337,333335 @@
 cttBtatcatatgctaKggNcataaaSatgtaaaDcDRtBggDtctttataattcBgtcg
-tactDtDagcctatttSVHtHttKtgtHMaSattgWaHKHttttagacatWatgtRgaaa
-NtactMcSMtYtcMgRtacttctWBacgaaatatagScDtttgaagacacatagtVgYgt
-cattHWtMMWcStgttaggKtSgaYaaccWStcgBttgcgaMttBYatcWtgacaYcaga
-gtaBDtRacttttcWatMttDBcatWtatcttactaBgaYtcttgttttttttYaaScYa
-HgtgttNtSatcMtcVaaaStccRcctDaataataStcYtRDSaMtDttgttSagtRRca
#### ~3.1 million similar lines follow ####
-taatataagctgcgccaggggatttttccagatcatctggcctgtgtatatgttcaaatc
+gacgaatatattagttatagtttactatccaaataaattaagcgaatcgaaataaactgt
+gacgaatatattagttatagtttactatccaaataaattaagcgaatcgaaataaactgt
+gacgaatatattagttatagtttactatccaaataaattaagcgaatcgaaataaactgt
#### ~208k identical lines follow
+gacgaatatattagttatagtttactatccaaataaattaagcgaatcgaaataaactgt
 taatagccgagagaaattac
../../mk/target.mk:101: recipe for target 'runtests' failed
make[2]: *** [runtests] Error 1
Failed making all in fasta: 1
../mk/ghc-recurse.mk:65: recipe for target 'all' failed
make[1]: *** [all] Error 1
Failed making all in shootout: 1
mk/ghc-recurse.mk:65: recipe for target 'all' failed
make: *** [all] Error 1

Trac metadata

Trac field	Value
Version	8.5
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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