llvm/test/CodeGen/X86/trunc-to-bool.ll
Andrew Trick 6a7770b7ae Enable MI Sched for x86.
This changes the SelectionDAG scheduling preference to source
order. Soon, the SelectionDAG scheduler can be bypassed saving
a nice chunk of compile time.

Performance differences that result from this change are often a
consequence of register coalescing. The register coalescer is far from
perfect. Bugs can be filed for deficiencies.

On x86 SandyBridge/Haswell, the source order schedule is often
preserved, particularly for small blocks.

Register pressure is generally improved over the SD scheduler's ILP
mode. However, we are still able to handle large blocks that require
latency hiding, unlike the SD scheduler's BURR mode. MI scheduler also
attempts to discover the critical path in single-block loops and
adjust heuristics accordingly.

The MI scheduler relies on the new machine model. This is currently
unimplemented for AVX, so we may not be generating the best code yet.

Unit tests are updated so they don't depend on SD scheduling heuristics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192750 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-15 23:33:07 +00:00

60 lines
1.4 KiB
LLVM

; An integer truncation to i1 should be done with an and instruction to make
; sure only the LSBit survives. Test that this is the case both for a returned
; value and as the operand of a branch.
; RUN: llc < %s -march=x86 | FileCheck %s
define zeroext i1 @test1(i32 %X) nounwind {
%Y = trunc i32 %X to i1
ret i1 %Y
}
; CHECK-LABEL: test1:
; CHECK: andl $1, %eax
define i1 @test2(i32 %val, i32 %mask) nounwind {
entry:
%shifted = ashr i32 %val, %mask
%anded = and i32 %shifted, 1
%trunced = trunc i32 %anded to i1
br i1 %trunced, label %ret_true, label %ret_false
ret_true:
ret i1 true
ret_false:
ret i1 false
}
; CHECK-LABEL: test2:
; CHECK: btl
define i32 @test3(i8* %ptr) nounwind {
%val = load i8* %ptr
%tmp = trunc i8 %val to i1
br i1 %tmp, label %cond_true, label %cond_false
cond_true:
ret i32 21
cond_false:
ret i32 42
}
; CHECK-LABEL: test3:
; CHECK: testb $1, (%eax)
define i32 @test4(i8* %ptr) nounwind {
%tmp = ptrtoint i8* %ptr to i1
br i1 %tmp, label %cond_true, label %cond_false
cond_true:
ret i32 21
cond_false:
ret i32 42
}
; CHECK-LABEL: test4:
; CHECK: testb $1, 4(%esp)
define i32 @test5(double %d) nounwind {
%tmp = fptosi double %d to i1
br i1 %tmp, label %cond_true, label %cond_false
cond_true:
ret i32 21
cond_false:
ret i32 42
}
; CHECK-LABEL: test5:
; CHECK: testb $1