diff options
| -rw-r--r-- | lib/Target/X86/README.txt | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index d2aaa59..cc689c4 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -544,9 +544,9 @@ entry: br label %cond_true cond_true: ; preds = %cond_true, %entry - %x.0.0 = phi int [ 0, %entry ], [ %tmp9, %cond_true ] ; <int> [#uses=3] - %t_addr.0.0 = phi int [ %t, %entry ], [ %tmp7, %cond_true ] ; <int> [#uses=1] - %tmp2 = getelementptr int* %a, int %x.0.0 ; <int*> [#uses=1] + %x.0.0 = phi int [ 0, %entry ], [ %tmp9, %cond_true ] + %t_addr.0.0 = phi int [ %t, %entry ], [ %tmp7, %cond_true ] + %tmp2 = getelementptr int* %a, int %x.0.0 %tmp3 = load int* %tmp2 ; <int> [#uses=1] %tmp5 = add int %t_addr.0.0, %x.0.0 ; <int> [#uses=1] %tmp7 = add int %tmp5, %tmp3 ; <int> [#uses=2] @@ -633,11 +633,12 @@ LBB1_1: #bb LBB1_2: #UnifiedReturnBlock ret -In the code above, the 'if' is turned into a 'switch' at the mid-level. It looks -like the 'lower to branches' mode could be improved a little here. In particular, -the fall-through to LBB1_3 doesn't need a branch. It would also be nice to -eliminate the redundant "cmp 6", maybe by lowering to a linear sequence of -compares if there are below a certain number of cases (instead of a binary sequence)? +In the code above, the 'if' is turned into a 'switch' at the mid-level. It +looks like the 'lower to branches' mode could be improved a little here. In +particular, the fall-through to LBB1_3 doesn't need a branch. It would also be +nice to eliminate the redundant "cmp 6", maybe by lowering to a linear sequence +of compares if there are below a certain number of cases (instead of a binary +sequence)? //===---------------------------------------------------------------------===// @@ -645,7 +646,7 @@ Compile: int %test(ulong *%tmp) { %tmp = load ulong* %tmp ; <ulong> [#uses=1] %tmp.mask = shr ulong %tmp, ubyte 50 ; <ulong> [#uses=1] - %tmp.mask = cast ulong %tmp.mask to ubyte ; <ubyte> [#uses=1] + %tmp.mask = cast ulong %tmp.mask to ubyte %tmp2 = and ubyte %tmp.mask, 3 ; <ubyte> [#uses=1] %tmp2 = cast ubyte %tmp2 to int ; <int> [#uses=1] ret int %tmp2 |