diff options
Diffstat (limited to 'src/amd/common')
| -rw-r--r-- | src/amd/common/ac_llvm_build.c | 24 | ||||
| -rw-r--r-- | src/amd/common/ac_llvm_build.h | 4 |
2 files changed, 28 insertions, 0 deletions
diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c index 20216a74947..180fd2414a5 100644 --- a/src/amd/common/ac_llvm_build.c +++ b/src/amd/common/ac_llvm_build.c @@ -763,3 +763,27 @@ ac_emit_sendmsg(struct ac_llvm_context *ctx, ac_emit_llvm_intrinsic(ctx, intr_name, ctx->voidt, args, 2, 0); } + +LLVMValueRef +ac_emit_imsb(struct ac_llvm_context *ctx, + LLVMValueRef arg, + LLVMTypeRef dst_type) +{ + LLVMValueRef msb = ac_emit_llvm_intrinsic(ctx, "llvm.AMDGPU.flbit.i32", + dst_type, &arg, 1, + AC_FUNC_ATTR_READNONE); + + /* The HW returns the last bit index from MSB, but NIR/TGSI wants + * the index from LSB. Invert it by doing "31 - msb". */ + msb = LLVMBuildSub(ctx->builder, LLVMConstInt(ctx->i32, 31, false), + msb, ""); + + LLVMValueRef all_ones = LLVMConstInt(ctx->i32, -1, true); + LLVMValueRef cond = LLVMBuildOr(ctx->builder, + LLVMBuildICmp(ctx->builder, LLVMIntEQ, + arg, LLVMConstInt(ctx->i32, 0, 0), ""), + LLVMBuildICmp(ctx->builder, LLVMIntEQ, + arg, all_ones, ""), ""); + + return LLVMBuildSelect(ctx->builder, cond, all_ones, msb, ""); +} diff --git a/src/amd/common/ac_llvm_build.h b/src/amd/common/ac_llvm_build.h index e88874ad46b..0ff04e4c703 100644 --- a/src/amd/common/ac_llvm_build.h +++ b/src/amd/common/ac_llvm_build.h @@ -182,6 +182,10 @@ void ac_emit_sendmsg(struct ac_llvm_context *ctx, uint32_t msg, LLVMValueRef wave_id); +LLVMValueRef ac_emit_imsb(struct ac_llvm_context *ctx, + LLVMValueRef arg, + LLVMTypeRef dst_type); + #ifdef __cplusplus } #endif |