On Tue, Jun 21, 2016 at 9:27 PM, Tom Stellard <t...@stellard.net> wrote:
> On Tue, Jun 21, 2016 at 08:17:15PM +0200, Marek Olšák wrote:
>> On Tue, Jun 21, 2016 at 7:21 PM, Tom Stellard <t...@stellard.net> wrote:
>> > On Mon, Jun 13, 2016 at 06:27:02PM +0200, Marek Olšák wrote:
>> >> From: Marek Olšák <marek.ol...@amd.com>
>> >>
>> >> ---
>> >> src/gallium/drivers/radeon/r600_pipe_common.c | 1 +
>> >> src/gallium/drivers/radeon/r600_pipe_common.h | 1 +
>> >> src/gallium/drivers/radeonsi/si_shader.c | 16 ++++++++++++++++
>> >> 3 files changed, 18 insertions(+)
>> >>
>> >> diff --git a/src/gallium/drivers/radeon/r600_pipe_common.c
>> >> b/src/gallium/drivers/radeon/r600_pipe_common.c
>> >> index fa9f70d..5d4a679 100644
>> >> --- a/src/gallium/drivers/radeon/r600_pipe_common.c
>> >> +++ b/src/gallium/drivers/radeon/r600_pipe_common.c
>> >> @@ -482,6 +482,7 @@ static const struct debug_named_value
>> >> common_debug_options[] = {
>> >> { "sisched", DBG_SI_SCHED, "Enable LLVM SI Machine Instruction
>> >> Scheduler." },
>> >> { "mono", DBG_MONOLITHIC_SHADERS, "Use old-style monolithic shaders
>> >> compiled on demand" },
>> >> { "noce", DBG_NO_CE, "Disable the constant engine"},
>> >> + { "unsafemath", DBG_UNSAFE_MATH, "Enable unsafe math shader
>> >> optimizations" },
>> >>
>> >> DEBUG_NAMED_VALUE_END /* must be last */
>> >> };
>> >> diff --git a/src/gallium/drivers/radeon/r600_pipe_common.h
>> >> b/src/gallium/drivers/radeon/r600_pipe_common.h
>> >> index 77dfc4f..263ef5e 100644
>> >> --- a/src/gallium/drivers/radeon/r600_pipe_common.h
>> >> +++ b/src/gallium/drivers/radeon/r600_pipe_common.h
>> >> @@ -99,6 +99,7 @@
>> >> #define DBG_SI_SCHED (1llu << 46)
>> >> #define DBG_MONOLITHIC_SHADERS (1llu << 47)
>> >> #define DBG_NO_CE (1llu << 48)
>> >> +#define DBG_UNSAFE_MATH (1llu << 49)
>> >>
>> >> #define R600_MAP_BUFFER_ALIGNMENT 64
>> >> #define R600_MAX_VIEWPORTS 16
>> >> diff --git a/src/gallium/drivers/radeonsi/si_shader.c
>> >> b/src/gallium/drivers/radeonsi/si_shader.c
>> >> index 6dc4985..bba6a55 100644
>> >> --- a/src/gallium/drivers/radeonsi/si_shader.c
>> >> +++ b/src/gallium/drivers/radeonsi/si_shader.c
>> >> @@ -5255,6 +5255,22 @@ static void si_create_function(struct
>> >> si_shader_context *ctx,
>> >> else
>> >> LLVMAddAttribute(P, LLVMInRegAttribute);
>> >> }
>> >> +
>> >> + if (ctx->screen->b.debug_flags & DBG_UNSAFE_MATH) {
>> >> + /* These were copied from some LLVM test. */
>> >> + LLVMAddTargetDependentFunctionAttr(ctx->radeon_bld.main_fn,
>> >> + "less-precise-fpmad",
>> >> + "true");
>> >> + LLVMAddTargetDependentFunctionAttr(ctx->radeon_bld.main_fn,
>> >> + "no-infs-fp-math",
>> >> + "true");
>> >> + LLVMAddTargetDependentFunctionAttr(ctx->radeon_bld.main_fn,
>> >> + "no-nans-fp-math",
>> >> + "true");
>> >> + LLVMAddTargetDependentFunctionAttr(ctx->radeon_bld.main_fn,
>> >> + "unsafe-fp-math",
>> >> + "true");
>> >> + }
>> >
>> > You may get better results by also adding the fast-math flags to the
>> > individual floating-point instructions, but this would be a more
>> > invasive change.
>>
>> Is there sample code showing how to do that?
>>
>
> Something like this
> https://cgit.freedesktop.org/~tstellar/mesa/commit/?h=fast-math&id=4fa18fdde3a2b51b2371064bc27729fd1038c219
>
> There are more flags than just the UnsafeAlgebra that is used in the
> patch.
setUnsafeAlgebra enables all flags, not just UnsafeAlgebra.
Do the flags apply to whole expression trees or just one instruction?
Marek
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