From d839749ae8d6a69a650eca2e53842921c679f30d Mon Sep 17 00:00:00 2001 From: Nirav Dave Date: Tue, 18 Jul 2017 20:06:24 +0000 Subject: [DAG] Improve Aliasing of operations to static alloca Re-recommiting after landing DAG extension-crash fix. Recommiting after adding check to avoid miscomputing alias information on addresses of the same base but different subindices. Memory accesses offset from frame indices may alias, e.g., we may merge write from function arguments passed on the stack when they are contiguous. As a result, when checking aliasing, we consider the underlying frame index's offset from the stack pointer. Static allocs are realized as stack objects in SelectionDAG, but its offset is not set until post-DAG causing DAGCombiner's alias check to consider access to static allocas to frequently alias. Modify isAlias to consider access between static allocas and access from other frame objects to be considered aliasing. Many test changes are included here. Most are fixes for tests which indirectly relied on our aliasing ability and needed to be modified to preserve their original intent. The remaining tests have minor improvements due to relaxed ordering. The exception is CodeGen/X86/2011-10-19-widen_vselect.ll which has a minor degradation dispite though the pre-legalized DAG is improved. Reviewers: rnk, mkuper, jonpa, hfinkel, uweigand Reviewed By: rnk Subscribers: sdardis, nemanjai, javed.absar, llvm-commits Differential Revision: https://reviews.llvm.org/D33345 llvm-svn: 308350 --- llvm/test/CodeGen/X86/hipe-cc64.ll | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'llvm/test/CodeGen/X86/hipe-cc64.ll') diff --git a/llvm/test/CodeGen/X86/hipe-cc64.ll b/llvm/test/CodeGen/X86/hipe-cc64.ll index 43e2e1409fd..efe07cf6301 100644 --- a/llvm/test/CodeGen/X86/hipe-cc64.ll +++ b/llvm/test/CodeGen/X86/hipe-cc64.ll @@ -57,11 +57,7 @@ entry: store i64 %arg2, i64* %arg2_var store i64 %arg3, i64* %arg3_var - ; CHECK: movq 40(%rsp), %r15 - ; CHECK-NEXT: movq 32(%rsp), %rbp - ; CHECK-NEXT: movq 24(%rsp), %rsi - ; CHECK-NEXT: movq 16(%rsp), %rdx - ; CHECK-NEXT: movq 8(%rsp), %rcx + ; Loads are reading values just writen from corresponding register and are therefore noops. %0 = load i64, i64* %hp_var %1 = load i64, i64* %p_var %2 = load i64, i64* %arg0_var -- cgit v1.2.3