mirror of
https://github.com/RPCSX/llvm.git
synced 2024-12-13 14:46:53 +00:00
f50125ecaa
example code:
unsigned foo(unsigned x, unsigned y) {
if (x != 0) y--;
return y;
}
before:
_foo: ## @foo
cmpl $1, 4(%esp) ## encoding: [0x83,0x7c,0x24,0x04,0x01]
sbbl %eax, %eax ## encoding: [0x19,0xc0]
notl %eax ## encoding: [0xf7,0xd0]
addl 8(%esp), %eax ## encoding: [0x03,0x44,0x24,0x08]
ret ## encoding: [0xc3]
after:
_foo: ## @foo
cmpl $1, 4(%esp) ## encoding: [0x83,0x7c,0x24,0x04,0x01]
movl 8(%esp), %eax ## encoding: [0x8b,0x44,0x24,0x08]
adcl $-1, %eax ## encoding: [0x83,0xd0,0xff]
ret ## encoding: [0xc3]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122455 91177308-0d34-0410-b5e6-96231b3b80d8
135 lines
3.0 KiB
LLVM
135 lines
3.0 KiB
LLVM
; RUN: llc < %s -march=x86 | FileCheck %s -check-prefix=X32
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; RUN: llc < %s -march=x86-64 | FileCheck %s -check-prefix=X64
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; The immediate can be encoded in a smaller way if the
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; instruction is a sub instead of an add.
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define i32 @test1(i32 inreg %a) nounwind {
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%b = add i32 %a, 128
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ret i32 %b
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; X32: subl $-128, %eax
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; X64: subl $-128,
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}
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define i64 @test2(i64 inreg %a) nounwind {
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%b = add i64 %a, 2147483648
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ret i64 %b
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; X32: addl $-2147483648, %eax
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; X64: subq $-2147483648,
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}
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define i64 @test3(i64 inreg %a) nounwind {
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%b = add i64 %a, 128
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ret i64 %b
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; X32: addl $128, %eax
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; X64: subq $-128,
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}
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define i1 @test4(i32 %v1, i32 %v2, i32* %X) nounwind {
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entry:
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%t = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %v1, i32 %v2)
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%sum = extractvalue {i32, i1} %t, 0
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%obit = extractvalue {i32, i1} %t, 1
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br i1 %obit, label %overflow, label %normal
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normal:
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store i32 0, i32* %X
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br label %overflow
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overflow:
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ret i1 false
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; X32: test4:
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; X32: addl
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; X32-NEXT: jo
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; X64: test4:
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; X64: addl %esi, %edi
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; X64-NEXT: jo
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}
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define i1 @test5(i32 %v1, i32 %v2, i32* %X) nounwind {
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entry:
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%t = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %v1, i32 %v2)
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%sum = extractvalue {i32, i1} %t, 0
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%obit = extractvalue {i32, i1} %t, 1
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br i1 %obit, label %carry, label %normal
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normal:
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store i32 0, i32* %X
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br label %carry
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carry:
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ret i1 false
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; X32: test5:
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; X32: addl
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; X32-NEXT: jb
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; X64: test5:
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; X64: addl %esi, %edi
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; X64-NEXT: jb
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}
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declare {i32, i1} @llvm.sadd.with.overflow.i32(i32, i32)
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declare {i32, i1} @llvm.uadd.with.overflow.i32(i32, i32)
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define i64 @test6(i64 %A, i32 %B) nounwind {
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%tmp12 = zext i32 %B to i64 ; <i64> [#uses=1]
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%tmp3 = shl i64 %tmp12, 32 ; <i64> [#uses=1]
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%tmp5 = add i64 %tmp3, %A ; <i64> [#uses=1]
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ret i64 %tmp5
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; X32: test6:
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; X32: movl 12(%esp), %edx
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; X32-NEXT: addl 8(%esp), %edx
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; X32-NEXT: movl 4(%esp), %eax
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; X32-NEXT: ret
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; X64: test6:
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; X64: shlq $32, %rsi
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; X64: leaq (%rsi,%rdi), %rax
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; X64: ret
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}
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define {i32, i1} @test7(i32 %v1, i32 %v2) nounwind {
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%t = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %v1, i32 %v2)
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ret {i32, i1} %t
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}
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; X64: test7:
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; X64: addl %esi, %eax
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; X64-NEXT: setb %dl
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; X64-NEXT: ret
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; PR5443
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define {i64, i1} @test8(i64 %left, i64 %right) nounwind {
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entry:
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%extleft = zext i64 %left to i65
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%extright = zext i64 %right to i65
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%sum = add i65 %extleft, %extright
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%res.0 = trunc i65 %sum to i64
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%overflow = and i65 %sum, -18446744073709551616
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%res.1 = icmp ne i65 %overflow, 0
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%final0 = insertvalue {i64, i1} undef, i64 %res.0, 0
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%final1 = insertvalue {i64, i1} %final0, i1 %res.1, 1
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ret {i64, i1} %final1
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}
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; X64: test8:
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; X64: addq
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; X64-NEXT: sbbq
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; X64-NEXT: testb
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define i32 @test9(i32 %x, i32 %y) nounwind readnone {
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%cmp = icmp eq i32 %x, 10
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%sub = sext i1 %cmp to i32
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%cond = add i32 %sub, %y
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ret i32 %cond
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; X64: test9:
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; X64: cmpl $10
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; X64: sete
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; X64: subl
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; X64: ret
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}
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