From fb1d2cc9f18f3515379a5e329f8da3bd919a91d4 Mon Sep 17 00:00:00 2001
From: Austin Seipp <austin@well-typed.com>
Date: Fri, 25 Oct 2013 22:33:52 -0500
Subject: [PATCH] Revert "comments"
This reverts commit 9026c77a07533bda3773c3c3f3df1c6592bc80c7.
---
compiler/codeGen/StgCmmLayout.hs | 27 ---------------------------
1 file changed, 27 deletions(-)
diff --git a/compiler/codeGen/StgCmmLayout.hs b/compiler/codeGen/StgCmmLayout.hs
index 2153430ac5ec..84736429bc90 100644
--- a/compiler/codeGen/StgCmmLayout.hs
+++ b/compiler/codeGen/StgCmmLayout.hs
@@ -188,7 +188,6 @@ slowCall fun stg_args
" with pat " ++ unpackFS rts_fun)
return r
- -- Note [avoid intermediate PAPs]
let n_args = length stg_args
if n_args > arity && optLevel dflags >= 2
then do
@@ -225,32 +224,6 @@ slowCall fun stg_args
return r
--- Note [avoid intermediate PAPs]
---
--- A slow call which needs multiple generic apply patterns will be
--- almost guaranteed to create one or more intermediate PAPs when
--- applied to a function that takes the correct number of arguments.
--- We try to avoid this situation by generating code to test whether
--- we are calling a function with the correct number of arguments
--- first, i.e.:
---
--- if (TAG(f) != 0} { // f is not a thunk
--- if (f->info.arity == n) {
--- ... make a fast call to f ...
--- }
--- }
--- ... otherwise make the slow call ...
---
--- We *only* do this when the call requires multiple generic apply
--- functions, which requires pushing extra stack frames and probably
--- results in intermediate PAPs. (I say probably, because it might be
--- that we're over-applying a function, but that seems even less
--- likely).
---
--- This very rarely applies, but if it does happen in an inner loop it
--- can have a severe impact on performance (#6084).
-
-
--------------
direct_call :: String
-> Convention -- e.g. NativeNodeCall or NativeDirectCall
--
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