[erlang-patches] [PATCH 2/2] hipe_arm.c: remove dead code
Mikael Pettersson
mikpe@REDACTED
Tue May 8 21:12:30 CEST 2012
erts/emulator/hipe/hipe_arm.c started out as a clone of hipe_ppc.c,
with #ifdefs to select ARM-specific code. Somehow those #ifdefs
never got cleaned out, resulting in fairly ugly-looking code.
This eliminates the #ifdefs, deletes dead PowerPC-specific code, and
keeps only the ARM-specific code. I've verified that the exact same
assembly code is generated for hipe_arm.c before and after this patch
(if you compile without -g, with -g there are unavoidable changes to
the debug data).
Signed-off-by: Mikael Pettersson <mikpe@REDACTED>
---
--- otp_src_R15B01/erts/emulator/hipe/hipe_arm.c.~1~ 2012-05-08 19:15:12.000000000 +0200
+++ otp_src_R15B01/erts/emulator/hipe/hipe_arm.c 2012-05-08 19:39:54.000000000 +0200
@@ -181,11 +181,9 @@ void *hipe_alloc_code(Uint nrbytes, Eter
curseg.base = base;
curseg.code_pos = base;
curseg.tramp_pos = (unsigned int*)((char*)base + SEGMENT_NRBYTES);
-#if defined(__arm__)
curseg.tramp_pos -= 2;
curseg.tramp_pos[0] = 0xE51FF004; /* ldr pc, [pc,#-4] */
curseg.tramp_pos[1] = (unsigned int)&nbif_callemu;
-#endif
address = try_alloc(nrwords, nrcallees, callees, trampvec);
if (!address) {
@@ -214,11 +212,9 @@ static unsigned int *alloc_stub(Uint nrw
curseg.base = base;
curseg.code_pos = base;
curseg.tramp_pos = (unsigned int*)((char*)base + SEGMENT_NRBYTES);
-#if defined(__arm__)
curseg.tramp_pos -= 2;
curseg.tramp_pos[0] = 0xE51FF004; /* ldr pc, [pc,#-4] */
curseg.tramp_pos[1] = (unsigned int)&nbif_callemu;
-#endif
address = try_alloc(nrwords, 0, NIL, NULL);
if (!address) {
@@ -269,10 +265,8 @@ int hipe_patch_insn(void *address, Uint3
void *hipe_make_native_stub(void *beamAddress, unsigned int beamArity)
{
unsigned int *code;
-#if defined(__arm__)
unsigned int *tramp_callemu;
int callemu_offset;
-#endif
/*
* Native code calls BEAM via a stub looking as follows:
@@ -288,13 +282,6 @@ void *hipe_make_native_stub(void *beamAd
* (Trampolines are allowed to modify r12, but they don't.)
*/
-#if !defined(__arm__)
- /* verify that 'ba' can reach nbif_callemu */
- if ((unsigned long)&nbif_callemu & ~0x01FFFFFCUL)
- abort();
-#endif
-
-#if defined(__arm__)
code = alloc_stub(4, &tramp_callemu);
if (!code)
abort();
@@ -304,11 +291,7 @@ void *hipe_make_native_stub(void *beamAd
if (!(callemu_offset >= -0x00800000 && callemu_offset <= 0x007FFFFF))
abort();
}
-#else
- code = alloc_stub(4, &trampoline);
-#endif
-#if defined(__arm__)
/* mov r0, #beamArity */
code[0] = 0xE3A00000 | (beamArity & 0xFF);
/* ldr r8, [pc,#0] // beamAddress */
@@ -317,16 +300,6 @@ void *hipe_make_native_stub(void *beamAd
code[2] = 0xEA000000 | (callemu_offset & 0x00FFFFFF);
/* .long beamAddress */
code[3] = (unsigned int)beamAddress;
-#else
- /* addi r12,0,beamAddress@REDACTED */
- code[0] = 0x39800000 | ((unsigned long)beamAddress & 0xFFFF);
- /* addi r0,0,beamArity */
- code[1] = 0x38000000 | (beamArity & 0x7FFF);
- /* addis r12,r12,beamAddress@REDACTED */
- code[2] = 0x3D8C0000 | at_ha((unsigned long)beamAddress);
- /* ba nbif_callemu */
- code[3] = 0x48000002 | (unsigned long)&nbif_callemu;
-#endif
hipe_flush_icache_range(code, 4*sizeof(int));
@@ -336,60 +309,32 @@ void *hipe_make_native_stub(void *beamAd
static void patch_b(Uint32 *address, Sint32 offset, Uint32 AA)
{
Uint32 oldI = *address;
-#if defined(__arm__)
Uint32 newI = (oldI & 0xFF000000) | (offset & 0x00FFFFFF);
-#else
- Uint32 newI = (oldI & 0xFC000001) | ((offset & 0x00FFFFFF) << 2) | (AA & 2);
-#endif
*address = newI;
hipe_flush_icache_word(address);
}
int hipe_patch_call(void *callAddress, void *destAddress, void *trampoline)
{
-#if !defined(__arm__)
- if ((Uint32)destAddress == ((Uint32)destAddress & 0x01FFFFFC)) {
- /* The destination is in the [0,32MB[ range.
- We can reach it with a ba/bla instruction.
- This is the typical case for BIFs and primops.
- It's also common for trap-to-BEAM stubs (on ppc32). */
- patch_b((Uint32*)callAddress, (Uint32)destAddress >> 2, 2);
+ Sint32 destOffset = ((Sint32)destAddress - ((Sint32)callAddress+8)) >> 2;
+ if (destOffset >= -0x800000 && destOffset <= 0x7FFFFF) {
+ /* The destination is within a [-32MB,+32MB[ range from us.
+ We can reach it with a b/bl instruction.
+ This is typical for nearby Erlang code. */
+ patch_b((Uint32*)callAddress, destOffset, 0);
} else {
-#endif
-#if defined(__arm__)
- Sint32 destOffset = ((Sint32)destAddress - ((Sint32)callAddress+8)) >> 2;
-#else
- Sint32 destOffset = ((Sint32)destAddress - (Sint32)callAddress) >> 2;
-#endif
- if (destOffset >= -0x800000 && destOffset <= 0x7FFFFF) {
- /* The destination is within a [-32MB,+32MB[ range from us.
- We can reach it with a b/bl instruction.
- This is typical for nearby Erlang code. */
- patch_b((Uint32*)callAddress, destOffset, 0);
- } else {
- /* The destination is too distant for b/bl/ba/bla.
- Must do a b/bl to the trampoline. */
-#if defined(__arm__)
- Sint32 trampOffset = ((Sint32)trampoline - ((Sint32)callAddress+8)) >> 2;
-#else
- Sint32 trampOffset = ((Sint32)trampoline - (Sint32)callAddress) >> 2;
-#endif
- if (trampOffset >= -0x800000 && trampOffset <= 0x7FFFFF) {
- /* Update the trampoline's address computation.
- (May be redundant, but we can't tell.) */
-#if defined(__arm__)
- patch_imm32((Uint32*)trampoline+1, (Uint32)destAddress);
-#else
- patch_li((Uint32*)trampoline, (Uint32)destAddress);
-#endif
- /* Update this call site. */
- patch_b((Uint32*)callAddress, trampOffset, 0);
- } else
- return -1;
- }
-#if !defined(__arm__)
+ /* The destination is too distant for b/bl.
+ Must do a b/bl to the trampoline. */
+ Sint32 trampOffset = ((Sint32)trampoline - ((Sint32)callAddress+8)) >> 2;
+ if (trampOffset >= -0x800000 && trampOffset <= 0x7FFFFF) {
+ /* Update the trampoline's address computation.
+ (May be redundant, but we can't tell.) */
+ patch_imm32((Uint32*)trampoline+1, (Uint32)destAddress);
+ /* Update this call site. */
+ patch_b((Uint32*)callAddress, trampOffset, 0);
+ } else
+ return -1;
}
-#endif
return 0;
}
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