[Mesa-dev] [PATCH] radv/ac: enable loop unrolling. (v2)
Michael Schellenberger Costa
mschellenbergercosta at googlemail.com
Fri Feb 24 07:06:41 UTC 2017
Hi Dave,
-----Ursprüngliche Nachricht-----
Von: mesa-dev [mailto:mesa-dev-bounces at lists.freedesktop.org] Im Auftrag von Dave Airlie
Gesendet: Freitag, 24. Februar 2017 04:59
An: mesa-dev at lists.freedesktop.org
Betreff: [Mesa-dev] [PATCH] radv/ac: enable loop unrolling. (v2)
From: Dave Airlie <airlied at redhat.com>
This enables LLVM loop unrolling.
v2: limit unroll count to 32, don't fully unroll. (arsenm)
Signed-off-by: Dave Airlie <airlied at redhat.com>
---
src/amd/common/ac_llvm_helper.cpp | 22 ++++++++++++++++++++++
src/amd/common/ac_llvm_util.h | 1 +
src/amd/common/ac_nir_to_llvm.c | 26 ++++++++++++++++++++++++--
3 files changed, 47 insertions(+), 2 deletions(-)
diff --git a/src/amd/common/ac_llvm_helper.cpp b/src/amd/common/ac_llvm_helper.cpp
index 594339e..85b0cbf 100644
--- a/src/amd/common/ac_llvm_helper.cpp
+++ b/src/amd/common/ac_llvm_helper.cpp
@@ -36,7 +36,9 @@
#include <llvm/Target/TargetOptions.h>
#include <llvm/ExecutionEngine/ExecutionEngine.h>
#include <llvm/IR/Attributes.h>
+#include <llvm/IR/LLVMContext.h>
+using namespace llvm;
If you have to use the namespace you should adopt the other lines below too
void ac_add_attr_dereferenceable(LLVMValueRef val, uint64_t bytes) {
llvm::Argument *A = llvm::unwrap<llvm::Argument>(val);
@@ -53,3 +55,23 @@ bool ac_is_sgpr_param(LLVMValueRef arg)
return AS.hasAttribute(ArgNo + 1, llvm::Attribute::ByVal) ||
AS.hasAttribute(ArgNo + 1, llvm::Attribute::InReg); }
^^^^
--Michael
+
+// MetadataAsValue uses a canonical format which strips the actual
+MDNode for // MDNode with just a single constant value, storing just a
+ConstantAsMetadata // This undoes this canonicalization, reconstructing the MDNode.
+static MDNode *extractMDNode(MetadataAsValue *MAV) {
+ Metadata *MD = MAV->getMetadata();
+ assert((isa<MDNode>(MD) || isa<ConstantAsMetadata>(MD)) &&
+ "Expected a metadata node or a canonicalized constant");
+
+ if (MDNode *N = dyn_cast<MDNode>(MD))
+ return N;
+ assert(0);
+ return MDNode::get(MAV->getContext(), MD); }
+
+void ac_metadata_point_op0_to_itself(LLVMValueRef v) {
+ MDNode *node = extractMDNode(unwrap<MetadataAsValue>(v));
+ node->replaceOperandWith(0, node);
+}
diff --git a/src/amd/common/ac_llvm_util.h b/src/amd/common/ac_llvm_util.h index 1f37a12..0d6c53c 100644
--- a/src/amd/common/ac_llvm_util.h
+++ b/src/amd/common/ac_llvm_util.h
@@ -48,6 +48,7 @@ LLVMTargetMachineRef ac_create_target_machine(enum radeon_family family, bool su
void ac_add_attr_dereferenceable(LLVMValueRef val, uint64_t bytes); bool ac_is_sgpr_param(LLVMValueRef param);
+void ac_metadata_point_op0_to_itself(LLVMValueRef v);
void
ac_add_function_attr(LLVMValueRef function, diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c index 9778581..d7a9a7b 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -3950,6 +3950,23 @@ static void visit_if(struct nir_to_llvm_context *ctx, nir_if *if_stmt)
LLVMPositionBuilderAtEnd(ctx->builder, merge_block); }
+static void set_unroll_metadata(struct nir_to_llvm_context *ctx,
+ LLVMValueRef br)
+{
+ unsigned kind = LLVMGetMDKindIDInContext(ctx->context, "llvm.loop", 9);
+ LLVMValueRef md_unroll;
+ LLVMValueRef part_arg = LLVMMDStringInContext(ctx->context, "llvm.loop.unroll.count", 22);
+ LLVMValueRef count_arg = LLVMConstInt(ctx->i32, 32, false);
+ LLVMValueRef args[2] = {part_arg, count_arg};
+ LLVMValueRef count = LLVMMDNodeInContext(ctx->context, args, 2);
+
+ LLVMValueRef md_args[] = {NULL, count};
+ md_unroll = LLVMMDNodeInContext(ctx->context, md_args, 2);
+ ac_metadata_point_op0_to_itself(md_unroll);
+
+ LLVMSetMetadata(br, kind, md_unroll);
+}
+
static void visit_loop(struct nir_to_llvm_context *ctx, nir_loop *loop) {
LLVMBasicBlockRef continue_parent = ctx->continue_block; @@ -3964,8 +3981,10 @@ static void visit_loop(struct nir_to_llvm_context *ctx, nir_loop *loop)
LLVMPositionBuilderAtEnd(ctx->builder, ctx->continue_block);
visit_cf_list(ctx, &loop->body);
- if (LLVMGetInsertBlock(ctx->builder))
- LLVMBuildBr(ctx->builder, ctx->continue_block);
+ if (LLVMGetInsertBlock(ctx->builder)) {
+ LLVMValueRef loop = LLVMBuildBr(ctx->builder, ctx->continue_block);
+ set_unroll_metadata(ctx, loop);
+ }
LLVMPositionBuilderAtEnd(ctx->builder, ctx->break_block);
ctx->continue_block = continue_parent; @@ -4827,10 +4846,13 @@ static void ac_llvm_finalize_module(struct nir_to_llvm_context * ctx)
/* Add some optimization passes */
LLVMAddScalarReplAggregatesPass(passmgr);
+ LLVMAddLoopRotatePass(passmgr);
LLVMAddLICMPass(passmgr);
LLVMAddAggressiveDCEPass(passmgr);
LLVMAddCFGSimplificationPass(passmgr);
LLVMAddInstructionCombiningPass(passmgr);
+ LLVMAddIndVarSimplifyPass(passmgr);
+ LLVMAddLoopUnrollPass(passmgr);
/* Run the pass */
LLVMInitializeFunctionPassManager(passmgr);
--
2.9.3
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