Function Layout, Global Variable Layout and Pooled Constants Layout Reordering

tests_lit/llvm2ice_tests/reorder-pooled-constants.ll

Index: tests_lit/llvm2ice_tests/reorder-pooled-constants.ll
diff --git a/tests_lit/llvm2ice_tests/fpconst.pnacl.ll b/tests_lit/llvm2ice_tests/reorder-pooled-constants.ll
similarity index 92%
copy from tests_lit/llvm2ice_tests/fpconst.pnacl.ll
copy to tests_lit/llvm2ice_tests/reorder-pooled-constants.ll
index 80c6f9fbadc767a1fd7498b9a62d99641d203928..c734ff8d1be7c7f6da6e8fa3c660db283478a384 100644
--- a/tests_lit/llvm2ice_tests/fpconst.pnacl.ll
+++ b/tests_lit/llvm2ice_tests/reorder-pooled-constants.ll
@@ -1,22 +1,13 @@
-; This is a smoke test for floating-point constant pooling.  It tests
-; pooling of various float and double constants (including positive
-; and negative NaN) within functions and across functions.  Note that
-; in LLVM bitcode, hex constants are used for an FP constant whenever
-; the constant "cannot be represented as a decimal floating point
-; number in a reasonable number of digits".  See
-; http://llvm.org/docs/LangRef.html#simple-constants .
+; This is a smoke test for reordering pooled constants.
+; This option is only implemented for target X8632 for now.
 
 ; RUN: %p2i --assemble --disassemble --filetype=obj --dis-flags=-s \
-; RUN:   -i %s --args -O2 --verbose none | FileCheck %s
-; RUN: %p2i --assemble --disassemble --filetype=obj --dis-flags=-s \
-; RUN:   -i %s --args -Om1 --verbose none | FileCheck %s
+; RUN:   --target x8632 -i %s --args -sz-seed=1 -O2 -reorder-pooled-constants \
+; RUN:   | FileCheck %s --check-prefix=X86O2
 
-; RUN: %if --need allow_dump --command %p2i --assemble --disassemble \
-; RUN:   --dis-flags=-s -i %s --args -O2 --verbose none \
-; RUN:  | %if --need allow_dump --command FileCheck %s
-; RUN: %if --need allow_dump --command %p2i --assemble --disassemble \
-; RUN:   --dis-flags=-s -i %s --args -Om1 --verbose none \
-; RUN:  | %if --need allow_dump --command FileCheck %s
+; RUN: %p2i --assemble --disassemble --filetype=obj --dis-flags=-s \
+; RUN:   --target x8632 -i %s --args -sz-seed=1 -Om1 -reorder-pooled-constants \
+; RUN:   | FileCheck %s --check-prefix=X86OM1
 
 @__init_array_start = internal constant [0 x i8] zeroinitializer, align 4
 @__fini_array_start = internal constant [0 x i8] zeroinitializer, align 4
@@ -541,17 +532,38 @@ return:                                           ; preds = %entry, %sw.bb65, %s
   ret double %retval.0
 }
 
-; The FP constant pool entries for each type are dumped in some
-; implementation-dependent order.  So for the purposes of lit, we just
-; pick one value for each type, and make sure it appears exactly once.
-
-; Check for float 0.5
-; CHECK-LABEL: .rodata.cst4
-; CHECK:     0000003f
-; CHECK-NOT: 0000003f
-
-; Check for double 0.5
-; CHECK-LABEL: .rodata.cst8
-; CHECK:     00000000 0000e03f
-; CHECK-NOT: 00000000 0000e03f
-; CHECK-LABEL: .text
+; Make sure the constants in pools are shuffled.
+; TODO(qining, stichnot): Om1 and O2 result into different sizes of i32 constant

[Jim Stichnoth, 2015/06/26 01:54:57]

This isn't really a TODO, just an explanation of the Om1/O2 differences.

[qining, 2015/06/26 03:16:08]

Done. Add following sentence to the top:
TODO(qining, stichnot): Unify the checkers for Om1 and O2 optimization levels.

+; pools. Because the shuffling routine of constant pools is applied to integer
+; constant pools first, the random number used for shuffling float and double
+; constant pools will be different for Om1 and O2, so is the order of the pooled
+; float and double constants. The source of this difference may includes: stack
+; frame size, strength reduction, etc.
+
+; Check for float pool
+; X86O2-LABEL: .rodata.cst4
+; X86O2: 00000040 0000c0ff 00000041 00000000
+; X86O2: 0000003f 0000803f 00008040 0000c07f
+; X86O2: 0000803e
+
+; Check for double pool
+; X86O2-LABEL: .rodata.cst8
+; X86O2: 55555555 5555d53f 00000000 0000f8ff
+; X86O2: 00000000 0000f87f 00000000 0000e03f
+; X86O2: 00000000 0000d03f 00000000 00000000
+
+; X86O2-LABEL: .text
+
+; Check for float pool
+; X86OM1-LABEL: .rodata.cst4
+; X86OM1: 0000803f 0000003f 00000040 0000c0ff
+; X86OM1: 00000000 00008040 0000c07f 0000803e
+; X86OM1: 00000041
+
+; Check for double pool
+; X86OM1-LABEL: .rodata.cst8
+; X86OM1: 00000000 0000e03f 00000000 0000f87f
+; X86OM1: 00000000 0000f8ff 00000000 0000d03f
+; X86OM1: 00000000 00000000 55555555 5555d53f
+
+; X86OM1-LABEL: .text