LLVM backend for 6502
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Chris Lattner 75592e4137 Implement dynamic allocas correctly. In particular, because we were copying
directly out of R1 (without using a CopyFromReg, which uses a chain), multiple
allocas were getting CSE'd together, producing bogus code.  For this:

int %foo(bool %X, int %A, int %B) {
        br bool %X, label %T, label %F
F:
        %G = alloca int
        %H = alloca int
        store int %A, int* %G
        store int %B, int* %H
        %R = load int* %G
        ret int %R
T:
        ret int 0
}

We were generating:

_foo:
        stwu r1, -16(r1)
        stw r31, 4(r1)
        or r31, r1, r1
        stw r1, 12(r31)
        cmpwi cr0, r3, 0
        bne cr0, .LBB_foo_2     ; T
.LBB_foo_1:     ; F
        li r2, 16
        subf r2, r2, r1   ;; One alloca
        or r1, r2, r2
        or r3, r1, r1
        or r1, r2, r2
        or r2, r1, r1
        stw r4, 0(r3)
        stw r5, 0(r2)
        lwz r3, 0(r3)
        lwz r1, 12(r31)
        lwz r31, 4(r31)
        lwz r1, 0(r1)
        blr
.LBB_foo_2:     ; T
        li r3, 0
        lwz r1, 12(r31)
        lwz r31, 4(r31)
        lwz r1, 0(r1)
        blr

Now we generate:

_foo:
        stwu r1, -16(r1)
        stw r31, 4(r1)
        or r31, r1, r1
        stw r1, 12(r31)
        cmpwi cr0, r3, 0
        bne cr0, .LBB_foo_2     ; T
.LBB_foo_1:     ; F
        or r2, r1, r1
        li r3, 16
        subf r2, r3, r2  ;; Alloca 1
        or r1, r2, r2
        or r2, r1, r1
        or r6, r1, r1
        subf r3, r3, r6  ;; Alloca 2
        or r1, r3, r3
        or r3, r1, r1
        stw r4, 0(r2)
        stw r5, 0(r3)
        lwz r3, 0(r2)
        lwz r1, 12(r31)
        lwz r31, 4(r31)
        lwz r1, 0(r1)
        blr
.LBB_foo_2:     ; T
        li r3, 0
        lwz r1, 12(r31)
        lwz r31, 4(r31)
        lwz r1, 0(r1)
        blr

This fixes Povray and SPASS with the dag isel, the last two failing cases.
Tommorow we will hopefully turn it on by default! :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23190 91177308-0d34-0410-b5e6-96231b3b80d8
2005-09-01 21:31:30 +00:00
autoconf For PR619: 2005-08-24 10:43:10 +00:00
docs Changed unsigned long to unsigned. 2005-08-26 09:25:54 +00:00
examples For PR616: 2005-08-24 10:07:20 +00:00
include/llvm First pass at the DAG Combiner. It isn't used anywhere yet, but it should 2005-09-01 00:19:25 +00:00
lib Implement dynamic allocas correctly. In particular, because we were copying 2005-09-01 21:31:30 +00:00
projects Implement PR614: 2005-08-27 18:50:39 +00:00
runtime Remove trailing whitespace 2005-04-21 23:48:37 +00:00
test Add regression test for efficient codegen of i32 x i32 -> hi32(i64) as 2005-09-01 00:04:03 +00:00
tools Allow bugpoint+PPC codegen to use fsqrt 2005-08-29 13:14:24 +00:00
utils Implement PR614: 2005-08-27 18:50:39 +00:00
win32 Update Visual Studio projects for removed file. 2005-08-19 13:51:22 +00:00
Xcode Remove Support/Search.h entry 2005-08-25 16:44:13 +00:00
.cvsignore Ignore the configure.out file generated by "make reconfigure" 2005-06-18 23:01:25 +00:00
configure For PR616: 2005-08-24 10:07:20 +00:00
CREDITS.TXT Add a note, people are responsible for requesting that they be added to the 2005-08-02 22:10:21 +00:00
LICENSE.TXT Remove extraneous colons after program names for consistency 2005-05-12 21:39:01 +00:00
llvm.spec Onward to LLVM-1.6 and beyond! 2005-05-18 20:23:20 +00:00
llvm.spec.in Onward to LLVM-1.6 and beyond! 2005-05-18 20:23:20 +00:00
Makefile For PR614: 2005-08-25 04:59:49 +00:00
Makefile.common Update comments to reflect new variable names. Patch contributed by 2005-02-14 16:02:19 +00:00
Makefile.config.in Two changes: 2005-04-22 17:14:14 +00:00
Makefile.rules Implement PR614: 2005-08-27 18:50:39 +00:00
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