From 21f09088d3c3d6d238c6b341d3f673feb2edc9be Mon Sep 17 00:00:00 2001 From: Manman Ren Date: Fri, 31 Jan 2014 00:42:44 +0000 Subject: PGO branch weight: update edge weights in SelectionDAGBuilder. When converting from "or + br" to two branches, or converting from "and + br" to two branches, we correctly update the edge weights of the two branches. The previous attempt at r200431 was reverted at r200434 because of two testing case failures. I modified my patch a little, but forgot to re-run "make check-all". Testing case CodeGen/ARM/lsr-unfolded-offset.ll is updated because of the patch's impact on branch probability which causes changes in spill placement. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200502 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/ARM/lsr-unfolded-offset.ll | 2 +- test/CodeGen/X86/MachineBranchProb.ll | 34 +++++++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 1 deletion(-) create mode 100644 test/CodeGen/X86/MachineBranchProb.ll (limited to 'test') diff --git a/test/CodeGen/ARM/lsr-unfolded-offset.ll b/test/CodeGen/ARM/lsr-unfolded-offset.ll index 26d4be2e06..1dafa0067b 100644 --- a/test/CodeGen/ARM/lsr-unfolded-offset.ll +++ b/test/CodeGen/ARM/lsr-unfolded-offset.ll @@ -4,7 +4,7 @@ ; register pressure and therefore spilling. There is more room for improvement ; here. -; CHECK: sub sp, #{{40|32|28|24}} +; CHECK: sub sp, #{{40|36|32|28|24}} ; CHECK: %for.inc ; CHECK-NOT: ldr diff --git a/test/CodeGen/X86/MachineBranchProb.ll b/test/CodeGen/X86/MachineBranchProb.ll new file mode 100644 index 0000000000..a8931527ea --- /dev/null +++ b/test/CodeGen/X86/MachineBranchProb.ll @@ -0,0 +1,34 @@ +; RUN: llc < %s -mtriple=x86_64-apple-darwin -print-machineinstrs=expand-isel-pseudos -o /dev/null 2>&1 | FileCheck %s + +;; Make sure a transformation in SelectionDAGBuilder that converts "or + br" to +;; two branches correctly updates the branch probability. + +@max_regno = common global i32 0, align 4 + +define void @test(i32* %old, i32 %final) { +for.cond: + br label %for.cond2 + +for.cond2: ; preds = %for.inc, %for.cond + %i.1 = phi i32 [ %inc19, %for.inc ], [ 0, %for.cond ] + %bit.0 = phi i32 [ %shl, %for.inc ], [ 1, %for.cond ] + %tobool = icmp eq i32 %bit.0, 0 + %v3 = load i32* @max_regno, align 4 + %cmp4 = icmp eq i32 %i.1, %v3 + %or.cond = or i1 %tobool, %cmp4 + br i1 %or.cond, label %for.inc20, label %for.inc, !prof !0 +; CHECK: BB#1: derived from LLVM BB %for.cond2 +; CHECK: Successors according to CFG: BB#3(56008718) BB#4(2203492365) +; CHECK: BB#4: derived from LLVM BB %for.cond2 +; CHECK: Successors according to CFG: BB#3(112017436) BB#2(4294967294) + +for.inc: ; preds = %for.cond2 + %shl = shl i32 %bit.0, 1 + %inc19 = add nsw i32 %i.1, 1 + br label %for.cond2 + +for.inc20: ; preds = %for.cond2 + ret void +} + +!0 = metadata !{metadata !"branch_weights", i32 112017436, i32 -735157296} -- cgit v1.2.3