diff options
Diffstat (limited to 'src/gallium/auxiliary/gallivm/lp_bld_arit_overflow.c')
| -rw-r--r-- | src/gallium/auxiliary/gallivm/lp_bld_arit_overflow.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit_overflow.c b/src/gallium/auxiliary/gallivm/lp_bld_arit_overflow.c new file mode 100644 index 0000000..43f2660 --- /dev/null +++ b/src/gallium/auxiliary/gallivm/lp_bld_arit_overflow.c @@ -0,0 +1,165 @@ +/************************************************************************** + * + * Copyright 2013 + * All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sub license, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial portions + * of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. + * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR + * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + * + **************************************************************************/ + + +/** + * @file + * Helper + * + * The functions in this file implement arthmetic operations with support + * for overflow detection and reporting. + * + */ + +#include "lp_bld_arit_overflow.h" + +#include "lp_bld_type.h" +#include "lp_bld_const.h" +#include "lp_bld_init.h" +#include "lp_bld_intr.h" +#include "lp_bld_logic.h" +#include "lp_bld_pack.h" +#include "lp_bld_debug.h" +#include "lp_bld_bitarit.h" + +#include "util/u_memory.h" +#include "util/u_debug.h" +#include "util/u_math.h" +#include "util/u_string.h" +#include "util/u_cpu_detect.h" + +#include <float.h> + + +static LLVMValueRef +build_binary_int_overflow(struct gallivm_state *gallivm, + const char *intr_prefix, + LLVMValueRef a, + LLVMValueRef b, + LLVMValueRef *ofbit) +{ + static const int MAX_INTR_STR = 256; + LLVMBuilderRef builder = gallivm->builder; + char intr_str[MAX_INTR_STR]; + LLVMTypeRef type_ref; + LLVMTypeKind type_kind; + LLVMTypeRef oelems[2] = { + LLVMInt32TypeInContext(gallivm->context), + LLVMInt1TypeInContext(gallivm->context) + }; + LLVMValueRef oresult; + LLVMTypeRef otype; + + debug_assert(LLVMTypeOf(a) == LLVMTypeOf(b)); + type_ref = LLVMTypeOf(a); + type_kind = LLVMGetTypeKind(type_ref); + + debug_assert(type_kind == LLVMIntegerTypeKind); + + switch (LLVMGetIntTypeWidth(type_ref)) { + case 16: + snprintf(intr_str, MAX_INTR_STR - 1, "%s.i16", + intr_prefix); + oelems[0] = LLVMInt16TypeInContext(gallivm->context); + break; + case 32: + snprintf(intr_str, MAX_INTR_STR - 1, "%s.i32", + intr_prefix); + oelems[0] = LLVMInt32TypeInContext(gallivm->context); + break; + case 64: + snprintf(intr_str, MAX_INTR_STR - 1, "%s.i64", + intr_prefix); + oelems[0] = LLVMInt64TypeInContext(gallivm->context); + break; + default: + debug_assert(!"Unsupported integer width in overflow computation!"); + } + + otype = LLVMStructTypeInContext(gallivm->context, oelems, 2, FALSE); + oresult = lp_build_intrinsic_binary(builder, intr_str, + otype, a, b); + if (ofbit) { + if (*ofbit) { + *ofbit = LLVMBuildOr( + builder, *ofbit, + LLVMBuildExtractValue(builder, oresult, 1, ""), ""); + } else { + *ofbit = LLVMBuildExtractValue(builder, oresult, 1, ""); + } + } + + return LLVMBuildExtractValue(builder, oresult, 0, ""); +} + +/** + * Performs unsigned addition of two integers and reports + * overflow if detected. + * + * The values @a and @b must be of the same integer type. If + * an overflow is detected the IN/OUT @ofbit parameter is used: + * - if it's pointing to a null value, the overflow bit is simply + * stored inside the variable it's pointing to, + * - if it's pointing to a valid value, then that variable, + * which must be of i1 type, is ORed with the newly detected + * overflow bit. This is done to allow chaining of a number of + * overflow functions together without having to test the + * overflow bit after every single one. + */ +LLVMValueRef +lp_build_uadd_overflow(struct gallivm_state *gallivm, + LLVMValueRef a, + LLVMValueRef b, + LLVMValueRef *ofbit) +{ + return build_binary_int_overflow(gallivm, "llvm.uadd.with.overflow", + a, b, ofbit); +} + +/** + * Performs unsigned multiplication of two integers and + * reports overflow if detected. + * + * The values @a and @b must be of the same integer type. If + * an overflow is detected the IN/OUT @ofbit parameter is used: + * - if it's pointing to a null value, the overflow bit is simply + * stored inside the variable it's pointing to, + * - if it's pointing to a valid value, then that variable, + * which must be of i1 type, is ORed with the newly detected + * overflow bit. This is done to allow chaining of a number of + * overflow functions together without having to test the + * overflow bit after every single one. + */ +LLVMValueRef +lp_build_umul_overflow(struct gallivm_state *gallivm, + LLVMValueRef a, + LLVMValueRef b, + LLVMValueRef *ofbit) +{ + return build_binary_int_overflow(gallivm, "llvm.umul.with.overflow", + a, b, ofbit); +} |