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20a35c3fa5
allows other simplifications. For example, this compiles:
int isnegative(unsigned int X) {
return !(X < 2147483648U);
}
Into this code:
x86:
movl 4(%esp), %eax
shrl $31, %eax
ret
arm:
mov r0, r0, lsr #31
bx lr
thumb:
lsr r0, r0, #31
bx lr
instead of:
x86:
cmpl $0, 4(%esp)
sets %al
movzbl %al, %eax
ret
arm:
mov r3, #0
cmp r0, #0
movlt r3, #1
mov r0, r3
bx lr
thumb:
mov r2, #1
mov r1, #0
cmp r0, #0
blt LBB1_2 @entry
LBB1_1: @entry
cpy r2, r1
LBB1_2: @entry
cpy r0, r2
bx lr
Testcase here: test/CodeGen/Generic/ispositive.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35883 91177308-0d34-0410-b5e6-96231b3b80d8
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