diff options
-rw-r--r-- | test/select.ll | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/test/select.ll b/test/select.ll index 69f794f..d937387 100644 --- a/test/select.ll +++ b/test/select.ll @@ -15,17 +15,24 @@ begin end ; A constant argument to a Phi produces a Cast instruction in the -; corresponding predecessor basic block. This has little to do with -; selection but the code is a bit weird. +; corresponding predecessor basic block. This checks a few things: +; -- phi arguments coming from the bottom of the same basic block +; (they should not be forward substituted in the machine code!) +; -- code generation for casts of various types +; -- use of immediate fields for integral constants of different sizes +; -- branch on a constant condition ; void "mergeConstants"(int * %x, int * %y) begin -; <label>:0 ; [#uses=1] +; <label>:0 br label %Top -Top: ; [#uses=4] - phi int [ 0, %0 ], [ 1, %Top ], [ 2, %Next ] ; <int>:0 [#uses=0] +Top: + phi int [ 0, %0 ], [ 1, %Top ], [ 524288, %Next ] + phi float [ 0.0, %0 ], [ 1.0, %Top ], [ 2.0, %Next ] + phi double [ 0.5, %0 ], [ 1.5, %Top ], [ 2.5, %Next ] + phi bool [ true, %0 ], [ false,%Top ], [ true, %Next ] br bool true, label %Top, label %Next -Next: ; [#uses=2] +Next: br label %Top end @@ -71,10 +78,12 @@ end ; Test cases where an LLVM instruction requires no machine ; instructions (e.g., cast int* to long). But there are 2 cases: -; 1. If the result register has only a single use, the operand will be -; copy-propagated during instruction selection. -; 2. If the result register has multiple uses, it cannot be copy -; propagated during instruction selection. It will generate a +; 1. If the result register has only a single use and the use is in the +; same basic block, the operand will be copy-propagated during +; instruction selection. +; 2. If the result register has multiple uses or is in a different +; basic block, it cannot (or will not) be copy propagated during +; instruction selection. It will generate a ; copy instruction (add-with-0), but this copy should get coalesced ; away by the register allocator. ; |