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llvmpipe: Don't use llvm.readcyclecounter. 

LLVM during optimization reorders the rdtsc instructions next to each
other, which makes it pretty useless.
This commit is contained in:
José Fonseca 2009-08-04 02:10:35 +01:00
parent 64611e086d
commit 5940ba26f7
1 changed files with 24 additions and 27 deletions
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51
src/gallium/drivers/llvmpipe/lp_test_blend.c
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@ -60,26 +60,19 @@
unsigned verbose = 0;
typedef int64_t (*blend_test_ptr_t)(const void *src, const void *dst, const void *con, void *res);
typedef void (*blend_test_ptr_t)(const void *src, const void *dst, const void *con, void *res);
static LLVMValueRef
read_cycle_counter(LLVMBuilderRef builder)
static INLINE uint64_t
rdtsc(void)
{
const char *name = "llvm.readcyclecounter";
LLVMModuleRef module = LLVMGetGlobalParent(LLVMGetBasicBlockParent(LLVMGetInsertBlock(builder)));
LLVMValueRef function;
function = LLVMGetNamedFunction(module, name);
if(!function) {
LLVMTypeRef type = LLVMInt64Type();
function = LLVMAddFunction(module, name, LLVMFunctionType(type, NULL, 0, 0));
LLVMSetFunctionCallConv(function, LLVMCCallConv);
LLVMSetLinkage(function, LLVMExternalLinkage);
}
assert(LLVMIsDeclaration(function));
return LLVMBuildCall(builder, function, NULL, 0, "");
#if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64)
uint32_t hi, lo;
__asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
return ((uint64_t)lo) | (((uint64_t)hi) << 32);
#else
return 0;
#endif
}
@ -102,14 +95,12 @@ add_blend_test(LLVMModuleRef module,
LLVMValueRef dst;
LLVMValueRef con;
LLVMValueRef res;
LLVMValueRef start_counter;
LLVMValueRef end_counter;
ret_type = LLVMInt64Type();
vec_type = lp_build_vec_type(type);
args[3] = args[2] = args[1] = args[0] = LLVMPointerType(vec_type, 0);
func = LLVMAddFunction(module, "test", LLVMFunctionType(LLVMInt64Type(), args, 4, 0));
func = LLVMAddFunction(module, "test", LLVMFunctionType(LLVMVoidType(), args, 4, 0));
LLVMSetFunctionCallConv(func, LLVMCCallConv);
src_ptr = LLVMGetParam(func, 0);
dst_ptr = LLVMGetParam(func, 1);
@ -124,17 +115,13 @@ add_blend_test(LLVMModuleRef module,
dst = LLVMBuildLoad(builder, dst_ptr, "dst");
con = LLVMBuildLoad(builder, const_ptr, "const");
start_counter = read_cycle_counter(builder);
res = lp_build_blend(builder, blend, type, src, dst, con, 3);
LLVMSetValueName(res, "res");
end_counter = read_cycle_counter(builder);
LLVMBuildStore(builder, res, res_ptr);
LLVMBuildRet(builder, LLVMBuildSub(builder, end_counter, start_counter, "cycles"));;
LLVMBuildRetVoid(builder);;
LLVMDisposeBuilder(builder);
return func;
@ -434,6 +421,9 @@ test_one(const struct pipe_blend_state *blend,
success = TRUE;
for(i = 0; i < n && success; ++i) {
int64_t start_counter = 0;
int64_t end_counter = 0;
if(type.floating && type.width == 32) {
float src[LP_MAX_VECTOR_LENGTH];
float dst[LP_MAX_VECTOR_LENGTH];
@ -450,7 +440,9 @@ test_one(const struct pipe_blend_state *blend,
for(j = 0; j < type.length; j += 4)
compute_blend_ref(blend, src + j, dst + j, con + j, ref + j);
cycles[i] = blend_test_ptr(src, dst, con, res);
start_counter = rdtsc();
blend_test_ptr(src, dst, con, res);
end_counter = rdtsc();
for(j = 0; j < type.length; ++j)
if(fabs(res[j] - ref[j]) > FLT_EPSILON)
@ -499,7 +491,9 @@ test_one(const struct pipe_blend_state *blend,
ref[j + k] = (uint8_t)(reff[k]*255.0f + 0.5f);
}
cycles[i] = blend_test_ptr(src, dst, con, res);
start_counter = rdtsc();
blend_test_ptr(src, dst, con, res);
end_counter = rdtsc();
for(j = 0; j < type.length; ++j) {
int delta = (int)res[j] - (int)ref[j];
@ -523,6 +517,8 @@ test_one(const struct pipe_blend_state *blend,
}
else
assert(0);
cycles[i] = end_counter - start_counter;
}
/*
@ -555,6 +551,7 @@ test_one(const struct pipe_blend_state *blend,
avg = sum/m;
fprintf(stdout, " cycles=%.1f", avg);
fprintf(stdout, " cycles_per_elem=%.1f", avg/type.length);
}
if(verbose >= 1) {