From 688c7d439fc77cdfae43af1cb9d235de28c6d090 Mon Sep 17 00:00:00 2001
From: florian <florian@freepascal.org>
Date: Fri, 11 Oct 2019 21:55:48 +0000
Subject: [PATCH] o AArch64:     * properly initialize FPU     * FMOV cannot
 throw an FPU exception

git-svn-id: trunk@43167 -
---
 compiler/aarch64/cgcpu.pas |  3 ++-
 rtl/aarch64/aarch64.inc    | 21 +++++++++++++++++----
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/compiler/aarch64/cgcpu.pas b/compiler/aarch64/cgcpu.pas
index ceb58563cc..4f1225dfc5 100644
--- a/compiler/aarch64/cgcpu.pas
+++ b/compiler/aarch64/cgcpu.pas
@@ -1024,6 +1024,7 @@ implementation
             { Notify the register allocator that we have written a move
               instruction so it can try to eliminate it. }
             add_move_instruction(instr);
+            { FMOV cannot generate a floating point exception }
           end
         else
           begin
@@ -1031,9 +1032,9 @@ implementation
                (reg_cgsize(reg2)<>tosize) then
               internalerror(2014110913);
             instr:=taicpu.op_reg_reg(A_FCVT,reg2,reg1);
+            maybe_check_for_fpu_exception(list);
           end;
         list.Concat(instr);
-        maybe_check_for_fpu_exception(list);
       end;
 
 
diff --git a/rtl/aarch64/aarch64.inc b/rtl/aarch64/aarch64.inc
index 25bdb3ca72..7903589662 100644
--- a/rtl/aarch64/aarch64.inc
+++ b/rtl/aarch64/aarch64.inc
@@ -121,21 +121,34 @@ procedure fpc_throwfpuexception;[public,alias:'FPC_THROWFPUEXCEPTION'];
   end;
 
 
-procedure fpc_enable_fpu_exceptions;
+{$define FPC_SYSTEM_HAS_SYSINITFPU}
+procedure SysInitFPU;
   begin
+    softfloat_rounding_mode:=rmNearest;
+    { 0 is rmNearest }
+    setfpcr(getfpcr and $ff3fffff);
     { clear all "exception happened" flags we care about}
     setfpsr(getfpsr and not(fpu_exception_mask shr fpu_exception_mask_to_status_mask_shift));
     { enable invalid operations and division by zero exceptions. }
-    setfpcr((getfpcr and not(fpu_exception_mask)));
-    softfloat_exception_mask:=[exPrecision,exUnderflow,exInvalidOp];
+    setfpcr(((getfpcr and not(fpu_exception_mask)) or fpu_dze or fpu_ofe or fpu_ioe));
+    softfloat_exception_mask:=[float_flag_underflow,float_flag_inexact,float_flag_denormal];
+    softfloat_exception_flags:=[];
   end;
 
 
+{$define FPC_SYSTEM_HAS_SYSRESETFPU}
+Procedure SysResetFPU;{$ifdef SYSTEMINLINE}inline;{$endif}
+begin
+  softfloat_exception_flags:=[];
+  setfpsr(getfpsr and not(FPSR_EXCEPTIONS));
+end;
+
+
 procedure fpc_cpuinit;
   begin
     { don't let libraries influence the FPU cw set by the host program }
     if not IsLibrary then
-      fpc_enable_fpu_exceptions;
+      SysInitFPU;
   end;