From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1005) id 5E352385800E; Sat, 29 Oct 2022 03:18:45 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5E352385800E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1667013525; bh=04eryp7hI+3HRy4FEpKRfel209Mx9X2mrHH++OoI+3Y=; h=From:To:Subject:Date:From; b=gkUWAK5ajFRzF2tb+MgmQ0r/+VtoyvSpMtzgFfEI55bY93/i4GGt5a/m1pr0gvwje KOvf4LZ8RHtE/rBlpmJPipS1jMyDB5jsOWLYBrp/XPPPhE6WW+2UGzavWRpZsrEpz+ WKbO366nOGPgjg86AqLw/ltl32Ur3BVsnoZF44NU= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Michael Meissner To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/users/meissner/heads/work101)] Update ChangeLog.meissner. X-Act-Checkin: gcc X-Git-Author: Michael Meissner X-Git-Refname: refs/users/meissner/heads/work101 X-Git-Oldrev: e2e9dc6129014a166cf67ab08366497c8f7a0595 X-Git-Newrev: c125caa3218c59e87c7637c66e721f8e1164507a Message-Id: <20221029031845.5E352385800E@sourceware.org> Date: Sat, 29 Oct 2022 03:18:45 +0000 (GMT) List-Id: https://gcc.gnu.org/g:c125caa3218c59e87c7637c66e721f8e1164507a commit c125caa3218c59e87c7637c66e721f8e1164507a Author: Michael Meissner Date: Fri Oct 28 23:17:55 2022 -0400 Update ChangeLog.meissner. 2022-10-28 Michael Meissner gcc/ * ChangeLog.meissner: Update. Diff: --- gcc/ChangeLog.meissner | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/gcc/ChangeLog.meissner b/gcc/ChangeLog.meissner index 143063f2a26..a55301f70c5 100644 --- a/gcc/ChangeLog.meissner +++ b/gcc/ChangeLog.meissner @@ -1,3 +1,71 @@ +==================== work101, patch #3 + +Update float 128-bit conversions. + +This patch is a rewrite of the patch submitted on August 18th: + +| https://gcc.gnu.org/pipermail/gcc-patches/2022-August/599988.html + +This patch reworks the conversions between 128-bit binary floating point types. +Previously, we would call rs6000_expand_float128_convert to do all conversions. +Now, we only define the conversions between the same representation that turn +into a NOP. The appropriate extend or truncate insn is generated, and after +register allocation, it is converted to a move. + +This patch also fixes two places where we want to override the external name +for the conversion function, and the wrong optab was used. Previously, +rs6000_expand_float128_convert would handle the move or generate the call as +needed. Now, it lets the machine independent code generate the call. But if +we use the machine independent code to generate the call, we need to update the +name for two optabs where a truncate would be used in terms of converting +between the modes. This patch updates those two optabs. + +While I know you feel the whole area needs to be rewritten, I would think it is +better to make things work incrementally rather than waiting for some grand +rewrite (that may or may not occur). + +With the current sources, we don't yet need this patch. But we will need this +patch when a future patch is submitted that will change the internal __float128 +type to use the _Float128 type when long double is IEEE 128-bit. I'm trying to +break out the smaller patches that each can stand alone, without having a +single larger patch. This future patch will fix various testsuite issues with +signalling NaNs when long double is IEEE 128-bit. + +I tested this patch on: + + 1) LE Power10 using --with-cpu=power10 --with-long-double-format=ieee + 2) LE Power10 using --with-cpu=power9 --with-long-double-format=ibm + 3) LE Power10 using --with-cpu=power8 --with-long-double-format=ibm + 4) LE Power10 using --with-cpu=power10 --with-long-double-format=ibm + 5) LE Power9 using --with-cpu=power9 --with-long-double-format=ibm + 6) BE Power7 using --with-cpu=power7 --with-long-double-format=ibm + +There were no regressions in the bootstrap process or running the tests. Can I +check this patch into the trunk? + +2022-10-28 Michael Meissner + +gcc/ + + * config/rs6000/rs6000.cc (init_float128_ieee): Use the correct + float_extend or float_truncate optab based on how the machine converts + between IEEE 128-bit and IBM 128-bit. + * config/rs6000/rs6000.md (IFKF): Delete. + (IFKF_reg): Delete. + (extendiftf2): Rewrite to be a move if IFmode and TFmode are both IBM + 128-bit. Do not run if TFmode is IEEE 128-bit. + (extendifkf2): Delete. + (extendtfkf2): Delete. + (extendtfif2): Delete. + (trunciftf2): Delete. + (truncifkf2): Delete. + (trunckftf2): Delete. + (extendkftf2): Implement conversion of IEEE 128-bit types as a move. + (trunctfif2): Delete. + (trunctfkf2): Implement conversion of IEEE 128-bit types as a move. + (extendtf2_internal): Delete. + (extendtf2_internal): Delete. + ==================== work101, patch #2 Make __float128 use the _Float128 type.