llvm/test/CodeGen/Mips/analyzebranch.ll
Daniel Sanders eacb2ec057 [mips] MIPS32R6 compact branch support
Summary:
MIPSR6 introduces a class of branches called compact branches. Unlike the
traditional MIPS branches which have a delay slot, compact branches do not
have a delay slot. The instruction following the compact branch is only
executed if the branch is not taken and must not be a branch.

It works by generating compact branches for MIPS32R6 when the delay slot
filler cannot fill a delay slot. Then, inspecting the generated code for
forbidden slot hazards (a compact branch with an adjacent branch or other
CTI) and inserting nops to clear this hazard.

Patch by Simon Dardis.

Reviewers: vkalintiris, dsanders

Subscribers: MatzeB, dsanders, llvm-commits

Differential Revision: http://reviews.llvm.org/D16353


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263444 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-14 16:24:05 +00:00

71 lines
2.6 KiB
LLVM

; RUN: llc -march=mips -mcpu=mips32 < %s | FileCheck %s -check-prefix=ALL -check-prefix=FCC
; RUN: llc -march=mips -mcpu=mips32r2 < %s | FileCheck %s -check-prefix=ALL -check-prefix=FCC
; RUN: llc -march=mips -mcpu=mips32r6 < %s | FileCheck %s -check-prefix=ALL -check-prefix=GPR -check-prefix=32-GPR
; RUN: llc -march=mips64 -mcpu=mips4 < %s | FileCheck %s -check-prefix=ALL -check-prefix=FCC
; RUN: llc -march=mips64 -mcpu=mips64 < %s | FileCheck %s -check-prefix=ALL -check-prefix=FCC
; RUN: llc -march=mips64 -mcpu=mips64r2 < %s | FileCheck %s -check-prefix=ALL -check-prefix=FCC
; RUN: llc -march=mips64 -mcpu=mips64r6 < %s | FileCheck %s -check-prefix=ALL -check-prefix=GPR -check-prefix=64-GPR
define double @foo(double %a, double %b) nounwind readnone {
entry:
; ALL-LABEL: foo:
; FCC: bc1f $BB
; FCC: nop
; 32-GPR: mtc1 $zero, $[[Z:f[0-9]]]
; 32-GPR: mthc1 $zero, $[[Z:f[0-9]]]
; 64-GPR: dmtc1 $zero, $[[Z:f[0-9]]]
; GPR: cmp.lt.d $[[FGRCC:f[0-9]+]], $[[Z]], $f12
; GPR: mfc1 $[[GPRCC:[0-9]+]], $[[FGRCC]]
; GPR-NOT: not $[[GPRCC]], $[[GPRCC]]
; GPR: bnezc $[[GPRCC]], $BB
%cmp = fcmp ogt double %a, 0.000000e+00
br i1 %cmp, label %if.end6, label %if.else
if.else: ; preds = %entry
%cmp3 = fcmp ogt double %b, 0.000000e+00
br i1 %cmp3, label %if.end6, label %return
if.end6: ; preds = %if.else, %entry
%c.0 = phi double [ %a, %entry ], [ 0.000000e+00, %if.else ]
%sub = fsub double %b, %c.0
%mul = fmul double %sub, 2.000000e+00
br label %return
return: ; preds = %if.else, %if.end6
%retval.0 = phi double [ %mul, %if.end6 ], [ 0.000000e+00, %if.else ]
ret double %retval.0
}
define void @f1(float %f) nounwind {
entry:
; ALL-LABEL: f1:
; FCC: bc1f $BB
; FCC: nop
; GPR: mtc1 $zero, $[[Z:f[0-9]]]
; GPR: cmp.eq.s $[[FGRCC:f[0-9]+]], $f12, $[[Z]]
; GPR: mfc1 $[[GPRCC:[0-9]+]], $[[FGRCC]]
; GPR-NOT: not $[[GPRCC]], $[[GPRCC]]
; 64-GPR beqzc $[[GPRCC]], $BB
; 32-GPR beqz $[[GPRCC]], $BB
%cmp = fcmp une float %f, 0.000000e+00
br i1 %cmp, label %if.then, label %if.end
if.then: ; preds = %entry
tail call void @abort() noreturn
unreachable
if.end: ; preds = %entry
tail call void (...) @f2() nounwind
ret void
}
declare void @abort() noreturn nounwind
declare void @f2(...)