Correct libgcc complex multiply excess precision handling (PR libgcc/77519).

libgcc complex multiply is meant to eliminate excess
precision from certain internal values by forcing them to memory in
exactly those cases where the type has excess precision.  But in
https://gcc.gnu.org/ml/gcc-patches/2014-09/msg01894.html I
accidentally inverted the logic so that values get forced to memory in
exactly the cases where it's not needed.  (This is a pessimization in
the no-excess-precision case, in principle could lead to bad results
depending on code generation in the excess-precision case.  Note: I do
not have a test demonstrating bad results.)

Bootstrapped with no regressions on x86_64-pc-linux-gnu.  Code size
went down on x86_64 as expected; old sizes:

   text    data     bss     dec     hex filename
    887       0       0     887     377 _muldc3.o
    810       0       0     810     32a _mulsc3.o
   2032       0       0    2032     7f0 _multc3.o
    983       0       0     983     3d7 _mulxc3.o

New sizes:

    847       0       0     847     34f _muldc3.o
    770       0       0     770     302 _mulsc3.o
   2032       0       0    2032     7f0 _multc3.o
    951       0       0     951     3b7 _mulxc3.o

	Backport from mainline
	2016-09-07  Joseph Myers  <joseph@codesourcery.com>

	PR libgcc/77519
	* libgcc2.c (NOTRUNC): Invert settings.

From-SVN: r240586

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index f3a2a8e37004ace10b3f01c6cde407435920362e..3087756ca5b00dd3f849b24dec20c01af2c49aa7 100644 (file)
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,11 @@
+2016-09-28  Joseph Myers  <joseph@codesourcery.com>
+
+       Backport from mainline
+       2016-09-07  Joseph Myers  <joseph@codesourcery.com>
+
+       PR libgcc/77519
+       * libgcc2.c (NOTRUNC): Invert settings.
+
 2016-08-31  Jakub Sejdak  <jakub.sejdak@phoesys.com>
 
        * config.host: Add support for arm*-*-phoenix* targets.

diff --git a/libgcc/libgcc2.c b/libgcc/libgcc2.c
index 0ef8823428a6c59e4d630a049f6afaef0e9f41d5..bd9078328fbdd7d666452967fe17023b4229a245 100644 (file)
--- a/libgcc/libgcc2.c
+++ b/libgcc/libgcc2.c
@@ -1866,25 +1866,25 @@ NAME (TYPE x, int m)
 # define CTYPE SCtype
 # define MODE  sc
 # define CEXT  __LIBGCC_SF_FUNC_EXT__
-# define NOTRUNC __LIBGCC_SF_EXCESS_PRECISION__
+# define NOTRUNC (!__LIBGCC_SF_EXCESS_PRECISION__)
 #elif defined(L_muldc3) || defined(L_divdc3)
 # define MTYPE DFtype
 # define CTYPE DCtype
 # define MODE  dc
 # define CEXT  __LIBGCC_DF_FUNC_EXT__
-# define NOTRUNC __LIBGCC_DF_EXCESS_PRECISION__
+# define NOTRUNC (!__LIBGCC_DF_EXCESS_PRECISION__)
 #elif defined(L_mulxc3) || defined(L_divxc3)
 # define MTYPE XFtype
 # define CTYPE XCtype
 # define MODE  xc
 # define CEXT  __LIBGCC_XF_FUNC_EXT__
-# define NOTRUNC __LIBGCC_XF_EXCESS_PRECISION__
+# define NOTRUNC (!__LIBGCC_XF_EXCESS_PRECISION__)
 #elif defined(L_multc3) || defined(L_divtc3)
 # define MTYPE TFtype
 # define CTYPE TCtype
 # define MODE  tc
 # define CEXT  __LIBGCC_TF_FUNC_EXT__
-# define NOTRUNC __LIBGCC_TF_EXCESS_PRECISION__
+# define NOTRUNC (!__LIBGCC_TF_EXCESS_PRECISION__)
 #else
 # error
 #endif