Re: [PATCH] RISC-V: Add -mstrict-align option

2017-05-05 Thread Palmer Dabbelt
On Thu, 04 May 2017 05:40:35 PDT (-0700), Palmer Dabbelt wrote: > From: Andrew Waterman > > The RISC-V user ISA permits misaligned accesses, but they may trap > and be emulated. That emulation software needs to be compiled assuming > strict alignment. > > Even when strict alignment is not require

[PATCH] RISC-V: Add -mstrict-align option

2017-05-04 Thread Palmer Dabbelt
From: Andrew Waterman The RISC-V user ISA permits misaligned accesses, but they may trap and be emulated. That emulation software needs to be compiled assuming strict alignment. Even when strict alignment is not required, set SLOW_UNALIGNED_ACCESS based upon -mtune to avoid a performance pitfal

Re: [PATCH] RISC-V: Add -mstrict-align option

2017-05-01 Thread Palmer Dabbelt
On Mon, 01 May 2017 10:08:08 PDT (-0700), san...@codesourcery.com wrote: > On 05/01/2017 09:40 AM, Palmer Dabbelt wrote: >> [snip] >> >> diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt >> index 0466bb2..0422e07 100644 >> --- a/gcc/config/riscv/riscv.opt >> +++ b/gcc/config/risc

Re: [PATCH] RISC-V: Add -mstrict-align option

2017-05-01 Thread Sandra Loosemore
On 05/01/2017 09:40 AM, Palmer Dabbelt wrote: [snip] diff --git a/gcc/config/riscv/riscv.opt b/gcc/config/riscv/riscv.opt index 0466bb2..0422e07 100644 --- a/gcc/config/riscv/riscv.opt +++ b/gcc/config/riscv/riscv.opt @@ -84,6 +84,10 @@ mcmodel= Target Report RejectNegative Joined Enum(code_mo

[PATCH] RISC-V: Add -mstrict-align option

2017-05-01 Thread Palmer Dabbelt
From: Andrew Waterman The RISC-V user ISA permits misaligned accesses, but they may trap and be emulated. That emulation software needs to be compiled assuming strict alignment. Even when strict alignment is not required, set SLOW_UNALIGNED_ACCESS based upon -mtune to avoid a performance pitfal