Subzero: Randomly insert nops.

tests_lit/llvm2ice_tests/nop-insertion.ll

+; This is a smoke test of nop insertion.
+
+; RUN: %llvm2ice -rng-seed=1 -insert-nops -nop-probability=50 %s | FileCheck %s

[jvoung (off chromium), 2014/08/14 15:17:17]

maybe test at 90% also, to test that the nop-probability matters / is not
inverted

[wala, 2014/08/14 23:29:50]

Done.

+
+define <4 x i32> @mul_v4i32(<4 x i32> %a, <4 x i32> %b) {
+entry:
+  %res = mul <4 x i32> %a, %b
+  ret <4 x i32> %res
+; CHECK-LABEL: mul_v4i32:
+; CHECK: sub esp, 48
+; CHECK: nop # length = 8 bytes
+; CHECK: movups  xmmword ptr [esp+32], xmm0
+; CHECK: movups  xmmword ptr [esp+16], xmm1
+; CHECK: nop     # length = 5 bytes
+; CHECK: movups  xmm2, xmmword ptr [esp+32]
+; CHECK: nop     # length = 7 bytes
+; CHECK: movups  xmm0, xmmword ptr [esp+32]
+; CHECK: movups  xmm1, xmmword ptr [esp+16]
+; CHECK: pshufd  xmm3, xmm0, 49
+; CHECK: pshufd  xmm4, xmm1, 49
+; CHECK: nop     # length = 9 bytes
+; CHECK: pmuludq xmm2, xmm1
+; CHECK: pmuludq xmm3, xmm4
+; CHECK: nop     # length = 1 byte
+; CHECK: shufps  xmm2, xmm3, 136
+; CHECK: pshufd  xmm5, xmm2, 216
+; CHECK: movups  xmmword ptr [esp], xmm5
+; CHECK: nop     # length = 8 bytes
+; CHECK: movups  xmm0, xmmword ptr [esp]
+; CHECK: nop     # length = 7 bytes
+; CHECK: add     esp, 48
+; CHECK: ret
+}