Commit 3c827be876a39cbe199e5cd7c6e90edef3a090b5 | zig

author	Andrew Kelley <andrew@ziglang.org> 2022-01-27 21:36:43-07:00
committer	Andrew Kelley <andrew@ziglang.org> 2022-01-28 11:45:04-07:00
log	3c827be876a39cbe199e5cd7c6e90edef3a090b5
tree	d13e5cec6df861361d523201ed922c5f6010af71
parent	4411f9c019f8f41baeacd39be01af9f961df4e4e

fix invalid const bitcast of f80

LLVM bitcast wants integers that match the number of bits. So the const
bitcast has to use an i80, not an i128.

This commit makes the behavior tests fail for me, so it seems I did not
correctly construct the type. But it gets rid of the LLVM segfault.

I noticed that the strategy of memcpy the buf worked if I simply did an
LLVMConstTrunc() on the i128 to make it into an i80 before the
LLVMConstBitCast().

But is that correct in the face of different endianness? I'm not sure.

1 files changed, 12 insertions(+), 4 deletions(-)

src
- stage1
  - codegen.cpp

src/stage1/codegen.cpp+12-4

 @@ -8094,10 +8094,18 @@ static LLVMValueRef gen_const_val(CodeGen *g, ZigValue *const_val, const char *n
                 case 64:
                     return LLVMConstReal(get_llvm_type(g, type_entry), const_val->data.x_f64);
                 case 80: {
-                    uint64_t buf[2];
+                    LLVMTypeRef llvm_i80 = LLVMIntType(80);
-                    memcpy(&buf, &const_val->data.x_f80, 16);
+                    LLVMValueRef x;
-                    LLVMValueRef as_int = LLVMConstIntOfArbitraryPrecision(LLVMInt128Type(), 2, buf);
+                    if (g->is_big_endian) {
-                    return LLVMConstBitCast(as_int, get_llvm_type(g, type_entry));
+                        x = LLVMConstInt(llvm_i80, const_val->data.x_f80.signExp, false);
+                        x = LLVMConstShl(x, LLVMConstInt(llvm_i80, 64, false));
+                        x = LLVMConstOr(x, LLVMConstInt(llvm_i80, const_val->data.x_f80.signif, false));
+                    } else {
+                        x = LLVMConstInt(llvm_i80, const_val->data.x_f80.signif, false);
+                        x = LLVMConstShl(x, LLVMConstInt(llvm_i80, 16, false));
+                        x = LLVMConstOr(x, LLVMConstInt(llvm_i80, const_val->data.x_f80.signExp, false));
+                    }
+                    return LLVMConstBitCast(x, get_llvm_type(g, type_entry));
                 }
                 case 128:
                     {