libphobos: RISC-V: Fix soft-float build errors with IEEE exception flags

Fix assembly errors:

.../libphobos/src/std/math.d: Assembler messages:.../libphobos/src/std/math.d:4773: Error: unrecognized opcode `frflags a0'.../libphobos/src/std/math.d:4856: Error: unrecognized opcode `fsflags a5'.../libphobos/src/std/math.d:4856: Error: unrecognized opcode `fsflags a5'.../libphobos/src/std/math.d:4773: Error: unrecognized opcode `frflags a0'.../libphobos/src/std/math.d:5549: Error: unrecognized opcode `fscsr a5'.../libphobos/src/std/math.d:5456: Error: unrecognized opcode `frcsr a5'.../libphobos/src/std/math.d:5456: Error: unrecognized opcode `frcsr a5'.../libphobos/src/std/math.d:5549: Error: unrecognized opcode `fscsr a5'.../libphobos/src/std/math.d:5456: Error: unrecognized opcode `frcsr a5'.../libphobos/src/std/math.d:5549: Error: unrecognized opcode `fscsr a0'.../libphobos/src/std/math.d:5456: Error: unrecognized opcode `frcsr a0'.../libphobos/src/std/math.d:5456: Error: unrecognized opcode `frcsr a0'.../libphobos/src/std/math.d:5549: Error: unrecognized opcode `fscsr s2'make[8]: *** [Makefile:1119: std/math.lo] Error 1

triggered with the RISC-V lp64 multilib in a GCC build configured with 
`--enable-multilib --enable-languages=all --target=riscv64-linux-gnu'. 
This is due to unconditional explicit use of F extension instructions 
within inline assembly, to access IEEE exception flags.  The use of 
these instructions is not allowed when building for a soft-float ABI.

Correct the problem by wrapping said inline assembly into a conditional 
such that if `D_SoftFloat' is true, then reads from IEEE exception flags 
return 0 and writes are ignored instead, complementing r270522 
("libphobos: Add D support for RISC-V Linux"), which is an updated 
version of <https://gcc.gnu.org/ml/gcc-patches/2019-04/msg00325.html>, 
where the problematic code has originated from.

libphobos/ChangeLog:

2019-05-02  Maciej W. Rozycki  <macro@wdc.com>

	* std/math.d (IeeeFlags.getIeeeFlags): Handle RISC-V soft-float ABI.
	(IeeeFlags.resetIeeeFlags): Likewise.
	(FloatingPointControl.getControlState): Likewise.
	(FloatingPointControl.setControlState): Likewise.

From-SVN: r270815
This commit is contained in:
Maciej W. Rozycki 2019-05-02 16:38:08 +00:00 committed by Iain Buclaw
parent 8c6a71e47c
commit 1770f16993
2 changed files with 40 additions and 13 deletions

View File

@ -1,3 +1,10 @@
2019-05-02 Maciej Rozycki <macro@wdc.com>
* std/math.d (IeeeFlags.getIeeeFlags): Handle RISC-V soft-float ABI.
(IeeeFlags.resetIeeeFlags): Likewise.
(FloatingPointControl.getControlState): Likewise.
(FloatingPointControl.setControlState): Likewise.
2019-04-25 Iain Buclaw <ibuclaw@gdcproject.org>
PR d/90250

View File

@ -4767,12 +4767,17 @@ private:
}
else version (RISCV_Any)
{
uint result = void;
asm pure nothrow @nogc
version (D_SoftFloat)
return 0;
else
{
"frflags %0" : "=r" result;
uint result = void;
asm pure nothrow @nogc
{
"frflags %0" : "=r" result;
}
return result;
}
return result;
}
else
assert(0, "Not yet supported");
@ -4850,10 +4855,15 @@ private:
}
else version (RISCV_Any)
{
uint newValues = 0x0;
asm pure nothrow @nogc
version (D_SoftFloat)
return;
else
{
"fsflags %0" : : "r" newValues;
uint newValues = 0x0;
asm pure nothrow @nogc
{
"fsflags %0" : : "r" newValues;
}
}
}
else
@ -5450,12 +5460,17 @@ private:
}
else version (RISCV_Any)
{
ControlState cont;
asm pure nothrow @nogc
version (D_SoftFloat)
return 0;
else
{
"frcsr %0" : "=r" cont;
ControlState cont;
asm pure nothrow @nogc
{
"frcsr %0" : "=r" cont;
}
return cont;
}
return cont;
}
else
assert(0, "Not yet supported");
@ -5544,9 +5559,14 @@ private:
}
else version (RISCV_Any)
{
asm pure nothrow @nogc
version (D_SoftFloat)
return;
else
{
"fscsr %0" : : "r" (newState);
asm pure nothrow @nogc
{
"fscsr %0" : : "r" (newState);
}
}
}
else