diff options
Diffstat (limited to 'src/amd/common')
| -rw-r--r-- | src/amd/common/ac_llvm_build.c | 56 | ||||
| -rw-r--r-- | src/amd/common/ac_llvm_build.h | 3 |
2 files changed, 59 insertions, 0 deletions
diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c index 6f577cdac7f..32d8a02f562 100644 --- a/src/amd/common/ac_llvm_build.c +++ b/src/amd/common/ac_llvm_build.c @@ -2435,3 +2435,59 @@ LLVMValueRef ac_unpack_param(struct ac_llvm_context *ctx, LLVMValueRef param, } return value; } + +/* Adjust the sample index according to FMASK. + * + * For uncompressed MSAA surfaces, FMASK should return 0x76543210, + * which is the identity mapping. Each nibble says which physical sample + * should be fetched to get that sample. + * + * For example, 0x11111100 means there are only 2 samples stored and + * the second sample covers 3/4 of the pixel. When reading samples 0 + * and 1, return physical sample 0 (determined by the first two 0s + * in FMASK), otherwise return physical sample 1. + * + * The sample index should be adjusted as follows: + * addr[sample_index] = (fmask >> (addr[sample_index] * 4)) & 0xF; + */ +void ac_apply_fmask_to_sample(struct ac_llvm_context *ac, LLVMValueRef fmask, + LLVMValueRef *addr, bool is_array_tex) +{ + struct ac_image_args fmask_load = {}; + fmask_load.opcode = ac_image_load; + fmask_load.resource = fmask; + fmask_load.dmask = 0xf; + fmask_load.da = is_array_tex; + + LLVMValueRef fmask_addr[4]; + memcpy(fmask_addr, addr, sizeof(fmask_addr[0]) * 3); + fmask_addr[3] = LLVMGetUndef(ac->i32); + + fmask_load.addr = ac_build_gather_values(ac, fmask_addr, + is_array_tex ? 4 : 2); + + LLVMValueRef fmask_value = ac_build_image_opcode(ac, &fmask_load); + fmask_value = LLVMBuildExtractElement(ac->builder, fmask_value, + ac->i32_0, ""); + + /* Apply the formula. */ + unsigned sample_chan = is_array_tex ? 3 : 2; + LLVMValueRef final_sample; + final_sample = LLVMBuildMul(ac->builder, addr[sample_chan], + LLVMConstInt(ac->i32, 4, 0), ""); + final_sample = LLVMBuildLShr(ac->builder, fmask_value, final_sample, ""); + final_sample = LLVMBuildAnd(ac->builder, final_sample, + LLVMConstInt(ac->i32, 0xF, 0), ""); + + /* Don't rewrite the sample index if WORD1.DATA_FORMAT of the FMASK + * resource descriptor is 0 (invalid), + */ + LLVMValueRef tmp; + tmp = LLVMBuildBitCast(ac->builder, fmask, ac->v8i32, ""); + tmp = LLVMBuildExtractElement(ac->builder, tmp, ac->i32_1, ""); + tmp = LLVMBuildICmp(ac->builder, LLVMIntNE, tmp, ac->i32_0, ""); + + /* Replace the MSAA sample index. */ + addr[sample_chan] = LLVMBuildSelect(ac->builder, tmp, final_sample, + addr[sample_chan], ""); +} diff --git a/src/amd/common/ac_llvm_build.h b/src/amd/common/ac_llvm_build.h index f901f336857..8b35028a314 100644 --- a/src/amd/common/ac_llvm_build.h +++ b/src/amd/common/ac_llvm_build.h @@ -414,6 +414,9 @@ LLVMValueRef ac_trim_vector(struct ac_llvm_context *ctx, LLVMValueRef value, LLVMValueRef ac_unpack_param(struct ac_llvm_context *ctx, LLVMValueRef param, unsigned rshift, unsigned bitwidth); +void ac_apply_fmask_to_sample(struct ac_llvm_context *ac, LLVMValueRef fmask, + LLVMValueRef *addr, bool is_array_tex); + #ifdef __cplusplus } #endif |