diff options
Diffstat (limited to 'test/CodeGen/X86/block-placement.ll')
| -rw-r--r-- | test/CodeGen/X86/block-placement.ll | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/test/CodeGen/X86/block-placement.ll b/test/CodeGen/X86/block-placement.ll index 859a702..16e98ed 100644 --- a/test/CodeGen/X86/block-placement.ll +++ b/test/CodeGen/X86/block-placement.ll @@ -395,8 +395,27 @@ exit: } define void @fpcmp_unanalyzable_branch(i1 %cond) { +; This function's CFG contains an unanalyzable branch that is likely to be +; split due to having a different high-probability predecessor. +; CHECK: fpcmp_unanalyzable_branch +; CHECK: %entry +; CHECK: %exit +; CHECK-NOT: %if.then +; CHECK-NOT: %if.end +; CHECK-NOT: jne +; CHECK-NOT: jnp +; CHECK: jne +; CHECK-NEXT: jnp +; CHECK-NEXT: %if.then + entry: - br i1 %cond, label %entry.if.then_crit_edge, label %lor.lhs.false +; Note that this branch must be strongly biased toward +; 'entry.if.then_crit_edge' to ensure that we would try to form a chain for +; 'entry' -> 'entry.if.then_crit_edge' -> 'if.then'. It is the last edge in that +; chain which would violate the unanalyzable branch in 'exit', but we won't even +; try this trick unless 'if.then' is believed to almost always be reached from +; 'entry.if.then_crit_edge'. + br i1 %cond, label %entry.if.then_crit_edge, label %lor.lhs.false, !prof !1 entry.if.then_crit_edge: %.pre14 = load i8* undef, align 1, !tbaa !0 @@ -418,3 +437,5 @@ if.then: if.end: ret void } + +!1 = metadata !{metadata !"branch_weights", i32 1000, i32 1} |