Increase heap space in runtime for benchmarks.

Otherwise we're essentially benchmarking garbage collecting,
which can give very inconsistent results.

Makefile

@@ -15,9 +15,10 @@ endif
 GHCOPTS=-fdiagnostics-color=always -j4 +RTS -A256m -RTS
 WEBSITE=../../web/pandoc.org
 REVISION?=1
-BENCHARGS?=--small --time-limit=2  --match=pattern $(PATTERN)
+# For gauge:
+BENCHARGS?=--small --ci=0.90 --match=pattern $(PATTERN) +RTS -T -A256m -I0 -RTS
 # For tasty-bench:
-# BENCHARGS?=--csv bench_$(TIMESTAMP).csv --timeout=6 +RTS -T -RTS $(if $(PATTERN),--pattern "$(PATTERN)",)
+# BENCHARGS?=--csv bench_$(TIMESTAMP).csv --timeout=6 +RTS -T -A256m -I0 -RTS $(if $(PATTERN),--pattern "$(PATTERN)",)
 
 quick:
 	stack install --ghc-options='$(GHCOPTS)' --install-ghc --flag 'pandoc:embed_data_files' --fast --test --ghc-options='$(GHCOPTS)' --test-arguments='-j4 --hide-successes $(TESTARGS)'
@@ -57,8 +58,8 @@ bench:
 	  --ghc-options '-Rghc-timing $(GHCOPTS)' \
 	  --benchmark-arguments='$(BENCHARGS)' 2>&1 | \
 	  tee "bench_latest.txt"
-	perl -pe 's/\x1b\[[0-9;]*[mGK]//g;s/\r//;' bench_latest.txt > \
-	  "bench_$(TIMESTAMP).txt"
+	perl -ne 'if (/\r/) { s/\x1b\[[0-9;]*[mGK]//g;s/^.*\r//;print; }' \
+	  bench_latest.txt > "bench_$(TIMESTAMP).txt"
 
 reformat:
 	for f in $(SOURCEFILES); do echo $$f; stylish-haskell -i $$f ; done

benchmark/benchmark-pandoc.hs

@@ -23,6 +23,7 @@ import Control.Monad.Except (throwError)
 import qualified Text.Pandoc.UTF8 as UTF8
 import qualified Data.ByteString as B
 import qualified Data.Text as T
+-- import Test.Tasty.Bench
 import Gauge
 import qualified Data.ByteString.Lazy as BL
 import Data.Maybe (mapMaybe)

pandoc.cabal

@@ -827,6 +827,7 @@ benchmark benchmark-pandoc
   build-depends:   bytestring,
                    containers,
                    gauge       >= 0.2     && < 0.3,
+                   -- tasty-bench >= 0.2     && <= 0.3,
                    mtl         >= 2.2     && < 2.3,
                    text        >= 1.1.1.0 && < 1.3,
                    time,

stack.yaml

@@ -13,6 +13,7 @@ extra-deps:
 - doclayout-0.3.0.2
 - citeproc-0.3.0.9
 - texmath-0.12.2
+- tasty-bench-0.2.2
 ghc-options:
    "$locals": -fhide-source-paths -Wno-missing-home-modules
 resolver: lts-17.5