Subzero: Randomize immediates by constant blinding or pooling.

tests_lit/llvm2ice_tests/randomize-immediates.ll

+; This is a smoke test of constant blinding and constant pooling.
+
+; RUN: %llvm2ice -O2 -rng-seed=1 -randomize-immediates=constant-blinding %s \
+; RUN:                                 | FileCheck %s --check-prefix=BLINDING
+; RUN: %llvm2ice -O2 -rng-seed=1 -randomize-immediates=constant-pooling %s \
+; RUN:                                 | FileCheck %s --check-prefix=POOLING
+
+define i32 @add_arg_plus_200000(i32 %arg) {
+entry:
+  %res = add i32 200000, %arg
+  ret i32 %res
+; BLINDING-LABEL: add_arg_plus_200000:
+; BLINDING: mov ecx, 16807
+; BLINDING: xor ecx, 216295

[Jim Stichnoth, 2014/08/13 23:30:26]

Instead of ecx, could you use a pattern that tests that the same register is
used in both instructions?

[wala, 2014/08/16 00:07:13]

Done.

+
+; POOLING-LABEL: add_arg_plus_200000:
+; POOLING: mov ecx, dword ptr [L$i32$0]

[Jim Stichnoth, 2014/08/13 23:30:26]

Instead of ecx, would it be reasonable test for any register?

[wala, 2014/08/16 00:07:13]

Done.

+}
+
+define float @load_arg_plus_200000(float* %arg) {
+entry:
+  %arg.int = ptrtoint float* %arg to i32
+  %addr.int = add i32 %arg.int, 200000
+  %addr.ptr = inttoptr i32 %addr.int to float*
+  %addr.load = load float* %addr.ptr, align 4
+  ret float %addr.load
+; BLINDING-LABEL: load_arg_plus_200000:
+; BLINDING: mov ecx, 282475249
+; BLINDING: xor ecx, 282408881
+; BLINDING: lea eax, dword ptr [eax+ecx]
+
+; POOLING-LABEL: load_arg_plus_200000:
+; POOLING: mov ecx, dword ptr [L$i32$0]
+; POOLING: lea eax, dword ptr [eax+ecx]
+}