llvm/lib/CodeGen/SelectionDAG
Chris Lattner 84734ce8ef Fix a bug in the 'store fpimm, ptr' -> 'store intimm, ptr' handling code.
Changing 'op' here caused us to not enter the store into a map, causing
reemission of the code!!  In practice, a simple loop like this:

no_exit:                ; preds = %no_exit, %entry
        %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=3]
        %tmp.4 = getelementptr "complex long double"* %P, uint %indvar, uint 0          ; <double*> [#uses=1]
        store double 0.000000e+00, double* %tmp.4
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=2]
        %exitcond = seteq uint %indvar.next, %N         ; <bool> [#uses=1]
        br bool %exitcond, label %return, label %no_exit

was being code gen'd to:

.LBBtest_1:     # no_exit
        movl %edx, %esi
        shll $4, %esi
        movl $0, 4(%eax,%esi)
        movl $0, (%eax,%esi)
        incl %edx
        movl $0, (%eax,%esi)
        movl $0, 4(%eax,%esi)
        cmpl %ecx, %edx
        jne .LBBtest_1  # no_exit

Note that we are doing 4 32-bit stores instead of 2.  Now we generate:

.LBBtest_1:     # no_exit
        movl %edx, %esi
        incl %esi
        shll $4, %edx
        movl $0, (%eax,%edx)
        movl $0, 4(%eax,%edx)
        cmpl %ecx, %esi
        movl %esi, %edx
        jne .LBBtest_1  # no_exit

This is much happier, though it would be even better if the increment of ESI
was scheduled after the compare :-/


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@20265 91177308-0d34-0410-b5e6-96231b3b80d8
2005-02-22 07:23:39 +00:00
..
LegalizeDAG.cpp Fix a bug in the 'store fpimm, ptr' -> 'store intimm, ptr' handling code. 2005-02-22 07:23:39 +00:00
Makefile Change Library Names Not To Conflict With Others When Installed 2004-10-27 23:18:45 +00:00
SelectionDAG.cpp Don't rely on doubles comparing identical to each other, which doesn't work 2005-02-17 20:17:32 +00:00
SelectionDAGISel.cpp Fix compilation errors with VS 2005, patch by Aaron Gray. 2005-02-17 21:39:27 +00:00
SelectionDAGPrinter.cpp Don't mash stuff together. 2005-01-16 07:28:31 +00:00
TargetLowering.cpp Add a hook to find out how the target handles shift amounts that are out of 2005-01-19 03:36:14 +00:00