[llvm-commits] [llvm] r171466 - in /llvm/trunk: lib/Target/X86/X86InstrArithmetic.td test/CodeGen/X86/early-ifcvt.ll

[Michael Gottesman]

Author: mgottesman
Date: Thu Jan  3 02:18:30 2013
New Revision: 171466

URL: http://llvm.org/viewvc/llvm-project?rev=171466&view=rev
Log:
Revert "Mark DIV/IDIV instructions hasSideEffects=1 because they can trap when dividing by 0. This is needed to keep early if conversion from moving them across basic blocks."

This reverts commit r171461 since it breaks the following tests:

Clang :: Analysis/outofbound-notwork.c
Clang :: Analysis/string-fail.c
Clang :: CXX/basic/basic.lookup/basic.lookup.qual/p6-0x.cpp
Clang :: CXX/basic/basic.lookup/basic.lookup.unqual/p15.cpp
Clang :: CXX/dcl.dcl/dcl.spec/dcl.fct.spec/p4.cpp
Clang :: CXX/dcl.dcl/dcl.spec/dcl.stc/p10.cpp
Clang :: CXX/temp/temp.param/p14.cpp
Clang :: CXX/temp/temp.res/temp.dep.res/temp.point/p1.cpp
Clang :: CodeGen/2009-02-13-zerosize-union-field-ppc.c
Clang :: CodeGen/blocks-2.c
Clang :: CodeGen/libcalls-d.c
Clang :: CodeGen/libcalls-ld.c
Clang :: CodeGenCXX/conversion-function.cpp
Clang :: CodeGenCXX/debug-info-limit-type.cpp
Clang :: CodeGenCXX/inheriting-constructor.cpp
Clang :: FixIt/fixit-errors.c
Clang :: FixIt/fixit-pmem.cpp
Clang :: Modules/namespaces.cpp
Clang :: PCH/changed-files.c
Clang :: PCH/pr4489.c
Clang :: PCH/source-manager-stack.c
Clang :: Parser/cxx-ambig-decl-expr-xfail.cpp
Clang :: SemaCXX/switch-implicit-fallthrough-cxx98.cpp
Clang :: SemaTemplate/instantiate-function-1.mm

Modified:
    llvm/trunk/lib/Target/X86/X86InstrArithmetic.td
    llvm/trunk/test/CodeGen/X86/early-ifcvt.ll

Modified: llvm/trunk/lib/Target/X86/X86InstrArithmetic.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86InstrArithmetic.td?rev=171466&r1=171465&r2=171466&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86InstrArithmetic.td (original)
+++ llvm/trunk/lib/Target/X86/X86InstrArithmetic.td Thu Jan  3 02:18:30 2013
@@ -266,7 +266,7 @@
 
 
 // unsigned division/remainder
-let hasSideEffects = 1 in { // so that we don't speculatively execute
+let hasSideEffects = 0 in {
 let Defs = [AL,EFLAGS,AX], Uses = [AX] in
 def DIV8r  : I<0xF6, MRM6r, (outs),  (ins GR8:$src),    // AX/r8 = AL,AH
                "div{b}\t$src", [], IIC_DIV8_REG>;

Modified: llvm/trunk/test/CodeGen/X86/early-ifcvt.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/early-ifcvt.ll?rev=171466&r1=171465&r2=171466&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/early-ifcvt.ll (original)
+++ llvm/trunk/test/CodeGen/X86/early-ifcvt.ll Thu Jan  3 02:18:30 2013
@@ -142,35 +142,3 @@
 }
 
 declare void @BZ2_bz__AssertH__fail()
-
-
-; Make sure we don't speculate on div/idiv instructions
-; CHECK: test_idiv
-; CHECK-NOT: cmov
-define i32 @test_idiv(i32 %a, i32 %b) nounwind uwtable readnone ssp {
-  %1 = icmp eq i32 %b, 0
-  br i1 %1, label %4, label %2
-
-; <label>:2                                       ; preds = %0
-  %3 = sdiv i32 %a, %b
-  br label %4
-
-; <label>:4                                       ; preds = %0, %2
-  %5 = phi i32 [ %3, %2 ], [ %a, %0 ]
-  ret i32 %5
-}
-
-; CHECK: test_div
-; CHECK-NOT: cmov
-define i32 @test_div(i32 %a, i32 %b) nounwind uwtable readnone ssp {
-  %1 = icmp eq i32 %b, 0
-  br i1 %1, label %4, label %2
-
-; <label>:2                                       ; preds = %0
-  %3 = udiv i32 %a, %b
-  br label %4
-
-; <label>:4                                       ; preds = %0, %2
-  %5 = phi i32 [ %3, %2 ], [ %a, %0 ]
-  ret i32 %5
-}