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llvm-project/llvm/test/CodeGen/X86/xor_not.ll

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Favors generating "not" over "xor -1". For example. unsigned test(unsigned a) { return ~a; } llvm used to generate: movl $4294967295, %eax xorl 4(%esp), %eax Now it generates: movl 4(%esp), %eax notl %eax It's 3 bytes shorter. llvm-svn: 62661
2009-01-21 10:09:05 +08:00
; RUN: llvm-as < %s | llc -march=x86 | grep {not\[lwb\]} | count 4
Add AsmPrinter support for emitting a directive to declare that the code being generated does not require an executable stack. Also, add target-specific code to make use of this on Linux on x86. llvm-svn: 50634
2008-05-05 08:28:39 +08:00
; RUN: llvm-as < %s | llc -march=x86-64 | grep {not\[lwb\]} | count 4
Prefer to expand mask for xor to -1, so we have a chance to turn it into a not. If it cannot be expanded, it will keep the old behaviour and try to shrink the constant. Part of enhancement for PR2191. llvm-svn: 49280
2008-04-07 05:23:02 +08:00
define i32 @test(i32 %a, i32 %b) nounwind {
entry:
%tmp1not = xor i32 %b, -2
%tmp3 = and i32 %tmp1not, %a
%tmp4 = lshr i32 %tmp3, 1
ret i32 %tmp4
}
define i32 @sum32(i32 %a, i32 %b) nounwind {
entry:
br label %bb
bb:
%b_addr.0 = phi i32 [ %b, %entry ], [ %tmp8, %bb ]
%a_addr.0 = phi i32 [ %a, %entry ], [ %tmp3, %bb ]
%tmp3 = xor i32 %a_addr.0, %b_addr.0
%tmp4not = xor i32 %tmp3, 2147483647
%tmp6 = and i32 %tmp4not, %b_addr.0
%tmp8 = shl i32 %tmp6, 1
%tmp10 = icmp eq i32 %tmp8, 0
br i1 %tmp10, label %bb12, label %bb
bb12:
ret i32 %tmp3
}
define i16 @sum16(i16 %a, i16 %b) nounwind {
entry:
br label %bb
bb:
%b_addr.0 = phi i16 [ %b, %entry ], [ %tmp8, %bb ]
%a_addr.0 = phi i16 [ %a, %entry ], [ %tmp3, %bb ]
%tmp3 = xor i16 %a_addr.0, %b_addr.0
%tmp4not = xor i16 %tmp3, 32767
%tmp6 = and i16 %tmp4not, %b_addr.0
%tmp8 = shl i16 %tmp6, 1
%tmp10 = icmp eq i16 %tmp8, 0
br i1 %tmp10, label %bb12, label %bb
bb12:
ret i16 %tmp3
}
define i8 @sum8(i8 %a, i8 %b) nounwind {
entry:
br label %bb
bb:
%b_addr.0 = phi i8 [ %b, %entry ], [ %tmp8, %bb ]
%a_addr.0 = phi i8 [ %a, %entry ], [ %tmp3, %bb ]
%tmp3 = xor i8 %a_addr.0, %b_addr.0
%tmp4not = xor i8 %tmp3, 127
%tmp6 = and i8 %tmp4not, %b_addr.0
%tmp8 = shl i8 %tmp6, 1
%tmp10 = icmp eq i8 %tmp8, 0
br i1 %tmp10, label %bb12, label %bb
bb12:
ret i8 %tmp3
}
fix this testcase to pass and remove a duplicate instance of itself. llvm-svn: 49281
2008-04-07 05:39:17 +08:00
define i32 @test2(i32 %a, i32 %b) nounwind {
Prefer to expand mask for xor to -1, so we have a chance to turn it into a not. If it cannot be expanded, it will keep the old behaviour and try to shrink the constant. Part of enhancement for PR2191. llvm-svn: 49280
2008-04-07 05:23:02 +08:00
entry:
br label %bb
bb:
%b_addr.0 = phi i32 [ %b, %entry ], [ %tmp8, %bb ]
%a_addr.0 = phi i32 [ %a, %entry ], [ %tmp3, %bb ]
%tmp3 = xor i32 %a_addr.0, %b_addr.0
%tmp4not = xor i32 %tmp3, 2147483646
%tmp6 = and i32 %tmp4not, %b_addr.0
%tmp8 = shl i32 %tmp6, 1
%tmp10 = icmp eq i32 %tmp8, 0
br i1 %tmp10, label %bb12, label %bb
bb12:
ret i32 %tmp3
}