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| author | gingerBill <bill@gingerbill.org> | 2021-03-30 20:38:04 +0100 |
|---|---|---|
| committer | gingerBill <bill@gingerbill.org> | 2021-03-30 20:38:04 +0100 |
| commit | 3359d0323a3115601b49ac7d6860c8b15babb491 (patch) | |
| tree | 7543035a8949c5762f292b601b8a4f0a4fd15d89 /src/llvm_backend.cpp | |
| parent | fbd01660ee8cff6d17e54e9e4b6ffd4e5011083b (diff) | |
Change `>>` behaviour in LLVM to prevent stupid UB
Diffstat (limited to 'src/llvm_backend.cpp')
| -rw-r--r-- | src/llvm_backend.cpp | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/src/llvm_backend.cpp b/src/llvm_backend.cpp index 92b180f73..e8028eece 100644 --- a/src/llvm_backend.cpp +++ b/src/llvm_backend.cpp @@ -6600,7 +6600,6 @@ handle_op: LLVMValueRef bits = rhs.value; LLVMValueRef bit_size = LLVMConstInt(lb_type(p->module, rhs.type), 8*type_size_of(lhs.type), false); - LLVMValueRef max = LLVMConstInt(lb_type(p->module, rhs.type), 8*type_size_of(lhs.type)-1, false); LLVMValueRef width_test = LLVMBuildICmp(p->builder, LLVMIntULT, bits, bit_size, ""); @@ -6617,16 +6616,17 @@ handle_op: bool is_unsigned = is_type_unsigned(type); LLVMValueRef bit_size = LLVMConstInt(lb_type(p->module, rhs.type), 8*type_size_of(lhs.type), false); - LLVMValueRef max = LLVMConstInt(lb_type(p->module, rhs.type), 8*type_size_of(lhs.type)-1, false); LLVMValueRef width_test = LLVMBuildICmp(p->builder, LLVMIntULT, bits, bit_size, ""); - bits = LLVMBuildSelect(p->builder, width_test, bits, max, ""); if (is_unsigned) { - res.value = LLVMBuildLShr(p->builder, lhs.value, bits, ""); + res.value = LLVMBuildLShr(p->builder, lhsval, bits, ""); } else { res.value = LLVMBuildAShr(p->builder, lhsval, bits, ""); } + + LLVMValueRef zero = LLVMConstNull(lb_type(p->module, lhs.type)); + res.value = LLVMBuildSelect(p->builder, width_test, res.value, zero, ""); return res; } case Token_AndNot: |