sunfishcode

--- vfprintf.c.orig     2019-01-08 16:56:58.147457674 -0800
+++ vfprintf.c  2019-01-11 13:49:08.320056831 -0800
@@ -11,6 +11,54 @@
 #include <math.h>
 #include <float.h>

+#if defined(WASM_NO_FLOATING_POINT_SUPPORT)
+
+__attribute__((__cold__, __noreturn__))
+static void floating_point_not_supported(void) {

sunfishcode

Cretonne IL is tuned for codegen. You can see this in the use of EBBs, br_table
not taking arguments, the lack of builtin def-use lists, the lack of a
general-purpose switch statement, the precense of instructions specialized to
take an immediate argument, and other places.

I'm entertaining the idea that this works out well for Rustc. It'll make
"fast compile" use cases, both "debug" and "pretty good optimization" builds
faster. Compared to LLVM's 4 layers in a typical compile (LLVM IR, SelectionDAG,
MachineFunction, MC), Cretonne uses one IL throughout, and it's designed
to be very compact.

sunfishcode

foo() -> Result<T, E>

When returning an Ok, foo would clear CF via "clc", and then return
the value as if the return type were just a plain T.

When returning an Err, foo would set the CF flag via "stc", and then
return the value as if the return type were just a plain E.

On the caller side, immediately after a call to foo, the caller could
do a "jc error_label". Fallthrough would be the success path and it'd

sunfishcode

    .globl      bar
    .p2align    4, 0x90
    .type       bar,@function
bar:
    .cfi_startproc
    cvttss2si   %xmm0, %eax
    cmpl        $1, %eax
    jo  0f
    retq
0:

sunfishcode

#include <stddef.h>
#include <stdbool.h>
#include <stdint.h>

bool is_valid_utf8(const uint8_t *str, size_t len)
{
  size_t bytes_seen = 0;
  size_t bytes_needed = 0;
  uint8_t lower_boundary = 0x80;
  uint8_t upper_boundary = 0xbf;

sunfishcode

Here's some C code:

void extern_func(int *, int*, int*, int*);

static int static_var = 3;
int global_var = 4;
extern int extern_var;

__attribute__((noinline))
static void static_func(void)

sunfishcode

 STACKTOP = STACKTOP + 8 | 0;
 $nHeight$i9409 = STACKTOP;
 STACKTOP = STACKTOP + 8 | 0;
 $nHeight$i9363 = STACKTOP;
 STACKTOP = STACKTOP + 8 | 0;
 $nHeight$i9316 = STACKTOP;
 STACKTOP = STACKTOP + 8 | 0;
 $nHeight$i9091 = STACKTOP;
 STACKTOP = STACKTOP + 8 | 0;
 $nHeight$i9044 = STACKTOP;