[X86] Use cast instead of dyn_cast and a null check marked unreachable.

[oota-llvm.git] / lib / Target / X86 / README-FPStack.txt

diff --git a/lib/Target/X86/README-FPStack.txt b/lib/Target/X86/README-FPStack.txt
index d94fa0219da41980042223589a60356448f4eb05..39efd2dbcf1adc2424434730fded2e60cd6759bf 100644 (file)
--- a/lib/Target/X86/README-FPStack.txt
+++ b/lib/Target/X86/README-FPStack.txt
@@ -9,20 +9,6 @@ http://gcc.gnu.org/ml/gcc-patches/2004-04/msg00659.html
 
 //===---------------------------------------------------------------------===//
 
-On darwin/x86, we should codegen:
-
-        ret double 0.000000e+00
-
-as fld0/ret, not as:
-
-        movl $0, 4(%esp)
-        movl $0, (%esp)
-        fldl (%esp)
-       ...
-        ret
-
-//===---------------------------------------------------------------------===//
-
 This should use fiadd on chips where it is profitable:
 double foo(double P, int *I) { return P+*I; }
 
@@ -41,8 +27,8 @@ def FpIADD32m : FpI<(ops RFP:$dst, RFP:$src1, i32mem:$src2), OneArgFPRW,
 
 //===---------------------------------------------------------------------===//
 
-The FP stackifier needs to be global.  Also, it should handle simple permutates
-to reduce number of shuffle instructions, e.g. turning:
+The FP stackifier should handle simple permutates to reduce number of shuffle
+instructions, e.g. turning:
 
 fld P  ->              fld Q
 fld Q                  fld P
@@ -94,6 +80,6 @@ foo:
        addl $20, %esp
        ret
 
-This will be solved when we go to a dynamic programming based isel.
+This just requires being smarter when custom expanding fptoui.
 
 //===---------------------------------------------------------------------===//