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| -rw-r--r-- | docs/GetElementPtr.html | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/docs/GetElementPtr.html b/docs/GetElementPtr.html index 49c3e6563a..08d8006e45 100644 --- a/docs/GetElementPtr.html +++ b/docs/GetElementPtr.html @@ -78,12 +78,13 @@ AType* Foo; ... X = &Foo->F;</pre> - <p>it is natural to think that there is only one index, the constant value - <tt>1</tt>. This results from C allowing you to treat pointers and arrays as - equivalent. LLVM doesn't. In this example, Foo is a pointer. That pointer must - be indexed. To arrive at the same address location as the C code, you would - provide the GEP instruction with two indices. The first indexes through the - pointer, the second index the element of the structure just as if it was:</p> + <p>it is natural to think that there is only one index, the selection of the + field <tt>F</tt>. However, in this example, <tt>Foo</tt> is a pointer. That + pointer must be indexed explicitly in LLVM. C, on the other hand, indexs + through it ransparently. To arrive at the same address location as the C + code, you would provide the GEP instruction with two index operands. The + first operand indexes through the pointer; the second operand indexes the + field <tt>F</tt> of the structure, just as if you wrote:</p> <pre> X = &Foo[0].F;</pre> <p>Sometimes this question gets rephrased as:</p> |