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  1. Oct 21, 2005
  2. Oct 20, 2005
    • Chris Lattner's avatar
      Do NOT touch FP ops with LSR. This fixes a testcase Nate sent me from an · 0c0b38bb
      Chris Lattner authored
      inner loop like this:
      
      LBB_RateConvertMono8AltiVec_2:  ; no_exit
              lis r2, ha16(.CPI_RateConvertMono8AltiVec_0)
              lfs f3, lo16(.CPI_RateConvertMono8AltiVec_0)(r2)
              fmr f3, f3
              fadd f0, f2, f0
              fadd f3, f0, f3
              fcmpu cr0, f3, f1
              bge cr0, LBB_RateConvertMono8AltiVec_2  ; no_exit
      
      to an inner loop like this:
      
      LBB_RateConvertMono8AltiVec_1:  ; no_exit
              fsub f2, f2, f1
              fcmpu cr0, f2, f1
              fmr f0, f2
              bge cr0, LBB_RateConvertMono8AltiVec_1  ; no_exit
      
      Doh! good catch!
      
      llvm-svn: 23838
      0c0b38bb
  3. Oct 18, 2005
  4. Oct 17, 2005
  5. Oct 11, 2005
  6. Oct 10, 2005
  7. Oct 09, 2005
  8. Oct 07, 2005
  9. Oct 04, 2005
  10. Oct 03, 2005
    • Chris Lattner's avatar
      Make IVUseShouldUsePostIncValue more aggressive when the use is a PHI. In · f07a587c
      Chris Lattner authored
      particular, it should realize that phi's use their values in the pred block
      not the phi block itself.  This change turns our em3d loop from this:
      
      _test:
              cmpwi cr0, r4, 0
              bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
      LBB_test_1:     ; entry.loopexit_crit_edge
              li r2, 0
              b LBB_test_6    ; loopexit
      LBB_test_2:     ; entry.no_exit_crit_edge
              li r6, 0
      LBB_test_3:     ; no_exit
              or r2, r6, r6
              lwz r6, 0(r3)
              cmpw cr0, r6, r5
              beq cr0, LBB_test_6     ; loopexit
      LBB_test_4:     ; endif
              addi r3, r3, 4
              addi r6, r2, 1
              cmpw cr0, r6, r4
              blt cr0, LBB_test_3     ; no_exit
      LBB_test_5:     ; endif.loopexit.loopexit_crit_edge
              addi r3, r2, 1
              blr
      LBB_test_6:     ; loopexit
              or r3, r2, r2
              blr
      
      into:
      
      _test:
              cmpwi cr0, r4, 0
              bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
      LBB_test_1:     ; entry.loopexit_crit_edge
              li r2, 0
              b LBB_test_5    ; loopexit
      LBB_test_2:     ; entry.no_exit_crit_edge
              li r6, 0
      LBB_test_3:     ; no_exit
              lwz r2, 0(r3)
              cmpw cr0, r2, r5
              or r2, r6, r6
              beq cr0, LBB_test_5     ; loopexit
      LBB_test_4:     ; endif
              addi r3, r3, 4
              addi r6, r6, 1
              cmpw cr0, r6, r4
              or r2, r6, r6
              blt cr0, LBB_test_3     ; no_exit
      LBB_test_5:     ; loopexit
              or r3, r2, r2
              blr
      
      
      Unfortunately, this is actually worse code, because the register coallescer
      is getting confused somehow.  If it were doing its job right, it could turn the
      code into this:
      
      _test:
              cmpwi cr0, r4, 0
              bgt cr0, LBB_test_2     ; entry.no_exit_crit_edge
      LBB_test_1:     ; entry.loopexit_crit_edge
              li r6, 0
              b LBB_test_5    ; loopexit
      LBB_test_2:     ; entry.no_exit_crit_edge
              li r6, 0
      LBB_test_3:     ; no_exit
              lwz r2, 0(r3)
              cmpw cr0, r2, r5
              beq cr0, LBB_test_5     ; loopexit
      LBB_test_4:     ; endif
              addi r3, r3, 4
              addi r6, r6, 1
              cmpw cr0, r6, r4
              blt cr0, LBB_test_3     ; no_exit
      LBB_test_5:     ; loopexit
              or r3, r6, r6
              blr
      
      ... which I'll work on next. :)
      
      llvm-svn: 23604
      f07a587c
    • Chris Lattner's avatar
      Refactor some code into a function · e4ed42a4
      Chris Lattner authored
      llvm-svn: 23603
      e4ed42a4
    • Chris Lattner's avatar
      This break is bogus and I have no idea why it was there. Basically it prevents · 360928db
      Chris Lattner authored
      memoizing code when IV's are used by phinodes outside of loops.  In a simple
      example, we were getting this code before (note that r6 and r7 are isomorphic
      IV's):
      
              li r6, 0
              or r7, r6, r6
      LBB_test_3:     ; no_exit
              lwz r2, 0(r3)
              cmpw cr0, r2, r5
              or r2, r7, r7
              beq cr0, LBB_test_5     ; loopexit
      LBB_test_4:     ; endif
              addi r2, r7, 1
              addi r7, r7, 1
              addi r3, r3, 4
              addi r6, r6, 1
              cmpw cr0, r6, r4
              blt cr0, LBB_test_3     ; no_exit
      
      Now we get:
      
              li r6, 0
      LBB_test_3:     ; no_exit
              or r2, r6, r6
              lwz r6, 0(r3)
              cmpw cr0, r6, r5
              beq cr0, LBB_test_6     ; loopexit
      LBB_test_4:     ; endif
              addi r3, r3, 4
              addi r6, r2, 1
              cmpw cr0, r6, r4
              blt cr0, LBB_test_3     ; no_exit
      
      this was noticed in em3d.
      
      llvm-svn: 23602
      360928db
    • Chris Lattner's avatar
      when checking if we should move a split edge block outside of a loop, · 8fcce170
      Chris Lattner authored
      check the presplit pred, not the post-split pred.  This was causing us
      to make the wrong decision in some cases, leaving the critical edge block
      in the loop.
      
      llvm-svn: 23601
      8fcce170
  11. Oct 01, 2005
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