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| author | Victor van den Elzen <victor.vde@gmail.com> | 2009-03-31 04:59:44 +0200 |
|---|---|---|
| committer | Victor van den Elzen <victor.vde@gmail.com> | 2010-07-24 22:00:12 +0200 |
| commit | ac732cb6a599836bf4c988e59ac6de4498758c72 (patch) | |
| tree | 9983e099a978cd40786f9529eb687a6d5a14d265 /nasm.c | |
| parent | 088d151130b427367766057feadd8351e03ee19b (diff) | |
| download | nasm-ac732cb6a599836bf4c988e59ac6de4498758c72.tar.gz nasm-ac732cb6a599836bf4c988e59ac6de4498758c72.tar.bz2 nasm-ac732cb6a599836bf4c988e59ac6de4498758c72.zip | |
Improve process_ea and introduce -OL
Two fixes:
1. Optimization of [bx+0xFFFF] etc
0xFFFF is an sbyte under 16-bit semantics,
so make sure to check it right.
2. Don't optimize displacements in -O0
Displacements that fit into an sbyte or
can be removed should *not* be optimized in -O0.
Implicit zero displacements are still optimized, e.g.:
[eax] -> 0 bit displacement, [ebp] -> 8 bit displacement.
However explicit displacements are not optimized:
[eax+0] -> 32 bit displacement, [ebp+0] -> 32 bit displacement.
Because #2 breaks compatibility with 0.98,
I introduced a new optimization level: -OL, legacy.
Diffstat (limited to 'nasm.c')
| -rw-r--r-- | nasm.c | 23 |
1 files changed, 16 insertions, 7 deletions
@@ -674,14 +674,22 @@ static bool process_arg(char *p, char *q) case '5': case '6': case '7': case '8': case '9': opt = strtoul(param, ¶m, 10); - /* -O0 -> optimizing == -1, 0.98 behaviour */ - /* -O1 -> optimizing == 0, 0.98.09 behaviour */ - if (opt < 2) - optimizing = opt - 1; + if (opt == 0) + /* no optimization */ + optimizing = -2; + else if (opt == 1) + /* 0.98.09 behaviour */ + optimizing = 0; else optimizing = opt; break; + case 'L': + /* 0.98 behaviour */ + param++; + optimizing = -1; + break; + case 'v': case '+': param++; @@ -783,10 +791,11 @@ static bool process_arg(char *p, char *q) " -F format select a debugging format\n\n" " -I<path> adds a pathname to the include file path\n"); printf - (" -O<digit> optimize branch offsets\n" - " -O0: No optimization (default)\n" + (" -O<digit> optimize code size\n" + " -O0: No optimization\n" + " -OL: Legacy optimization\n" " -O1: Minimal optimization\n" - " -Ox: Multipass optimization (recommended)\n\n" + " -Ox: Full optimization (default)\n\n" " -P<file> pre-includes a file\n" " -D<macro>[=<value>] pre-defines a macro\n" " -U<macro> undefines a macro\n" |