Add pat cms !defined($1)

Switch .cms to pass inputs and outputs on the real stack, not in
registers; like we do with .and, .or (81c677d) and .xor (c578c49).

At this point, nearly all functions in libem use the real stack, not
registers, for passing inputs and outputs.  This simplifies the ncg
table (which needs fewer lists of specific registers) but slows calls
to libem.

For example, after ba9b021, each call to .aar4 is about 10
instructions slower.  I moved 3 inputs and 1 output from registers to
the real stack.  A program would take 4 instructions to move registers
to stack, 4 to move stack to registers, and perhaps 2 to adjust the
stack pointer.

diff --git a/mach/powerpc/libem/cms.s b/mach/powerpc/libem/cms.s
index 5bcd310..0bcb1ab 100644 (file)
--- a/mach/powerpc/libem/cms.s
+++ b/mach/powerpc/libem/cms.s
@@ -1,18 +1,17 @@
 .sect .text
 
 ! Compare sets a, b.
-!  Stack: ( b a -- )
-!  With r3 = size of each set
-!  Yields r3 = 0 if equal, nonzero if not equal
+!  Stack: ( b a size -- result )
+!  Result is 0 if equal, nonzero if not equal.
 
 .define .cms
 .cms:
+       lwz     r3, 0(sp)               ! r3 = size of each set
        srwi    r7, r3, 2
        mtspr   ctr, r7                 ! ctr = size / 4
-       mr      r4, sp                  ! r4 = ptr to set a
-       add     r5, sp, r3              ! r5 = ptr to set b
+       addi    r4, sp, 4               ! r4 = ptr to set a
+       add     r5, r4, r3              ! r5 = ptr to set b
        li      r6, 0                   ! r6 = index
-       add     r9, r5, r3              ! r9 = future sp
 1:
        lwzx    r7, r4, r6
        lwzx    r8, r5, r6
@@ -20,10 +19,12 @@
        addi    r6, r6, 4
        bne     cr0, 2f                 ! branch if not equal
        bdnz    1b                      ! loop ctr times
-       li      r3, 0                   ! equal: return 0
+       li      r9, 0                   ! equal: return 0
        b       3f
 2:
-       li      r3, 1                   ! not equal: return 1
+       li      r9, 1                   ! not equal: return 1
 3:
-       mr      sp, r9                  ! remove sets from stack
+       slwi    r7, r3, 1
+       add     sp, sp, r7              ! adjust stack pointer
+       stw     r9, 0(sp)               ! push result
        blr

diff --git a/mach/powerpc/ncg/table b/mach/powerpc/ncg/table
index 7868f2a..84750df 100644 (file)
--- a/mach/powerpc/ncg/table
+++ b/mach/powerpc/ncg/table
@@ -1854,12 +1854,13 @@ PATTERNS
                        cmi INT32
 
        pat cms defined($1)
-               with STACK
-                       kills ALL
-                       gen
-                               move {CONST, $1}, R3
-                               bl {LABEL, ".cms"}
-                       yields R3
+               leaving
+                       loc $1
+                       cal ".cms"
+
+       pat cms !defined($1)
+               leaving
+                       cal ".cms"
 
 
 /* Other branching and labelling */