diff --git a/lib/Target/README.txt b/lib/Target/README.txt index 1c33f3946d3..8399115e598 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -167,44 +167,6 @@ if anyone cared enough about sincos. //===---------------------------------------------------------------------===// -Scalar Repl cannot currently promote this testcase to 'ret long cst': - - %struct.X = type { i32, i32 } - %struct.Y = type { %struct.X } - -define i64 @bar() { - %retval = alloca %struct.Y, align 8 - %tmp12 = getelementptr %struct.Y* %retval, i32 0, i32 0, i32 0 - store i32 0, i32* %tmp12 - %tmp15 = getelementptr %struct.Y* %retval, i32 0, i32 0, i32 1 - store i32 1, i32* %tmp15 - %retval.upgrd.1 = bitcast %struct.Y* %retval to i64* - %retval.upgrd.2 = load i64* %retval.upgrd.1 - ret i64 %retval.upgrd.2 -} - -it should be extended to do so. - -//===---------------------------------------------------------------------===// - --scalarrepl should promote this to be a vector scalar. - - %struct..0anon = type { <4 x float> } - -define void @test1(<4 x float> %V, float* %P) { - %u = alloca %struct..0anon, align 16 - %tmp = getelementptr %struct..0anon* %u, i32 0, i32 0 - store <4 x float> %V, <4 x float>* %tmp - %tmp1 = bitcast %struct..0anon* %u to [4 x float]* - %tmp.upgrd.1 = getelementptr [4 x float]* %tmp1, i32 0, i32 1 - %tmp.upgrd.2 = load float* %tmp.upgrd.1 - %tmp3 = mul float %tmp.upgrd.2, 2.000000e+00 - store float %tmp3, float* %P - ret void -} - -//===---------------------------------------------------------------------===// - Turn this into a single byte store with no load (the other 3 bytes are unmodified): @@ -634,32 +596,6 @@ once. //===---------------------------------------------------------------------===// -We should extend parameter attributes to capture more information about -pointer parameters for alias analysis. Some ideas: - -1. Add a "nocapture" attribute, which indicates that the callee does not store - the address of the parameter into a global or any other memory location - visible to the callee. This can be used to make basicaa and other analyses - more powerful. It is true for things like memcpy, strcat, and many other - things, including structs passed by value, most C++ references, etc. -2. Generalize readonly to be set on parameters. This is important mod/ref - info for the function, which is important for basicaa and others. It can - also be used by the inliner to avoid inserting a memcpy for byval - arguments when the function is inlined. - -These functions can be inferred by various analysis passes such as the -globalsmodrefaa pass. Note that getting #2 right is actually really tricky. -Consider this code: - -struct S; S G; -void caller(S byvalarg) { G.field = 1; ... } -void callee() { caller(G); } - -The fact that the caller does not modify byval arg is not enough, we need -to know that it doesn't modify G either. This is very tricky. - -//===---------------------------------------------------------------------===// - We should add an FRINT node to the DAG to model targets that have legal implementations of ceil/floor/rint. @@ -1690,6 +1626,19 @@ foo: //===---------------------------------------------------------------------===// +The arg promotion pass should make use of nocapture to make its alias analysis +stuff much more precise. + +//===---------------------------------------------------------------------===// + +The following functions should be optimized to use a select instead of a +branch (from gcc PR40072): + +char char_int(int m) {if(m>7) return 0; return m;} +int int_char(char m) {if(m>7) return 0; return m;} + +//===---------------------------------------------------------------------===// + Instcombine should replace the load with a constant in: static const char x[4] = {'a', 'b', 'c', 'd'}; @@ -1704,19 +1653,6 @@ is a null (making it a C string). There's no need for these restrictions. //===---------------------------------------------------------------------===// -The arg promotion pass should make use of nocapture to make its alias analysis -stuff much more precise. - -//===---------------------------------------------------------------------===// - -The following functions should be optimized to use a select instead of a -branch (from gcc PR40072): - -char char_int(int m) {if(m>7) return 0; return m;} -int int_char(char m) {if(m>7) return 0; return m;} - -//===---------------------------------------------------------------------===// - InstCombine's "turn load from constant into constant" optimization should be more aggressive in the presence of bitcasts. For example, because of unions, this code: