From 9586468c03ba9d0c488882eba1d870acd7adfd9e Mon Sep 17 00:00:00 2001 From: Jose Fonseca Date: Wed, 13 Apr 2016 15:41:55 +0100 Subject: [PATCH] gallivm: Workaround LLVM PR 27332. The credit for finding and isolating this bug goes to Vinson and Roland. The buggy LLVM versions were found by doing opt -instcombine llvm-pr27332.ll > /dev/null where llvm-pr27332.ll is the IR from https://llvm.org/bugs/show_bug.cgi?id=27332#c3 Reviewed-by: Roland Scheidegger --- src/gallium/auxiliary/gallivm/lp_bld_arit.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/src/gallium/auxiliary/gallivm/lp_bld_arit.c b/src/gallium/auxiliary/gallivm/lp_bld_arit.c index 9cb745e4cfe..beff4143fd8 100644 --- a/src/gallium/auxiliary/gallivm/lp_bld_arit.c +++ b/src/gallium/auxiliary/gallivm/lp_bld_arit.c @@ -1492,9 +1492,20 @@ lp_build_abs(struct lp_build_context *bld, return a; if(type.floating) { - char intrinsic[32]; - lp_format_intrinsic(intrinsic, sizeof intrinsic, "llvm.fabs", vec_type); - return lp_build_intrinsic_unary(builder, intrinsic, vec_type, a); + if (0x0306 <= HAVE_LLVM && HAVE_LLVM < 0x0309) { + /* Workaround llvm.org/PR27332 */ + LLVMTypeRef int_vec_type = lp_build_int_vec_type(bld->gallivm, type); + unsigned long long absMask = ~(1ULL << (type.width - 1)); + LLVMValueRef mask = lp_build_const_int_vec(bld->gallivm, type, ((unsigned long long) absMask)); + a = LLVMBuildBitCast(builder, a, int_vec_type, ""); + a = LLVMBuildAnd(builder, a, mask, ""); + a = LLVMBuildBitCast(builder, a, vec_type, ""); + return a; + } else { + char intrinsic[32]; + lp_format_intrinsic(intrinsic, sizeof intrinsic, "llvm.fabs", vec_type); + return lp_build_intrinsic_unary(builder, intrinsic, vec_type, a); + } } if(type.width*type.length == 128 && util_cpu_caps.has_ssse3) { -- 2.30.2