gcc/libgcc/ChangeLog:
2021-01-16 Daniel Engel <g...@danielengel.com>
Makefile.in (MPURE_CODE): New macro defines __PURE_CODE__.
(gcc_compile): Appended MPURE_CODE.
lib1funcs.S (FUNC_START_SECTION): Set flags for __PURE_CODE__.
clz2.S (__clzsi2): Added -mpure-code compatible instructions.
ctz2.S (__ctzsi2): Same.
popcnt.S (__popcountsi2, __popcountdi2): Same.
---
libgcc/Makefile.in | 5 ++++-
libgcc/config/arm/clz2.S | 25 ++++++++++++++++++++++-
libgcc/config/arm/ctz2.S | 38 +++++++++++++++++++++++++++++++++--
libgcc/config/arm/lib1funcs.S | 7 ++++++-
libgcc/config/arm/popcnt.S | 33 +++++++++++++++++++++++++-----
5 files changed, 98 insertions(+), 10 deletions(-)
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index 32e329f7764..e6b2ce5c6d7 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -307,6 +307,9 @@ CRTSTUFF_CFLAGS = -O2 $(GCC_CFLAGS) $(INCLUDES)
$(MULTILIB_CFLAGS) -g0 \
# Extra flags to use when compiling crt{begin,end}.o.
CRTSTUFF_T_CFLAGS =
+# Pass the -mpure-code flag into assembly for conditional compilation.
+MPURE_CODE = $(if $(findstring -mpure-code,$(CFLAGS)), -D__PURE_CODE__)
+
MULTIDIR := $(shell $(CC) $(CFLAGS) -print-multi-directory)
MULTIOSDIR := $(shell $(CC) $(CFLAGS) -print-multi-os-directory)
@@ -316,7 +319,7 @@ inst_slibdir = $(slibdir)$(MULTIOSSUBDIR)
gcc_compile_bare = $(CC) $(INTERNAL_CFLAGS) $(CFLAGS-$(<F))
compile_deps = -MT $@ -MD -MP -MF $(basename $@).dep
-gcc_compile = $(gcc_compile_bare) -o $@ $(compile_deps)
+gcc_compile = $(gcc_compile_bare) -o $@ $(compile_deps) $(MPURE_CODE)
gcc_s_compile = $(gcc_compile) -DSHARED
objects = $(filter %$(objext),$^)
diff --git a/libgcc/config/arm/clz2.S b/libgcc/config/arm/clz2.S
index a2de45ff651..97a44f5d187 100644
--- a/libgcc/config/arm/clz2.S
+++ b/libgcc/config/arm/clz2.S
@@ -214,17 +214,40 @@ FUNC_ENTRY clzsi2
IT(sub,ne) r2, #4
LLSYM(__clz2):
+ #if defined(__PURE_CODE__) && __PURE_CODE__
+ // Without access to table data, continue unrolling the loop.
+ lsrs r1, r0, #2
+
+ #ifdef __HAVE_FEATURE_IT
+ do_it ne,t
+ #else
+ beq LLSYM(__clz1)
+ #endif
+
+ // Out of 4 bits, the first '1' is somewhere in the highest 2,
+ // so the lower 2 bits are no longer interesting.
+ IT(mov,ne) r0, r1
+ IT(sub,ne) r2, #2
+
+ LLSYM(__clz1):
+ // Convert remainder {0,1,2,3} to {0,1,2,2}.
+ lsrs r1, r0, #1
+ bics r0, r1
+
+ #else /* !__PURE_CODE__ */
// Load the remainder by index
adr r1, LLSYM(__clz_remainder)
ldrb r0, [r1, r0]
+ #endif /* !__PURE_CODE__ */
#endif /* !__OPTIMIZE_SIZE__ */
// Account for the remainder.
subs r0, r2, r0
RET
- #if !defined(__OPTIMIZE_SIZE__) || !__OPTIMIZE_SIZE__
+ #if !(defined(__OPTIMIZE_SIZE__) && __OPTIMIZE_SIZE__) && \
+ !(defined(__PURE_CODE__) && __PURE_CODE__)
.align 2
LLSYM(__clz_remainder):
.byte 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4
diff --git a/libgcc/config/arm/ctz2.S b/libgcc/config/arm/ctz2.S
index b9528a061a2..6a49d64f3a6 100644
--- a/libgcc/config/arm/ctz2.S
+++ b/libgcc/config/arm/ctz2.S
@@ -209,11 +209,44 @@ FUNC_ENTRY ctzsi2
IT(sub,ne) r2, #4
LLSYM(__ctz2):
+ #if defined(__PURE_CODE__) && __PURE_CODE__
+ // Without access to table data, continue unrolling the loop.
+ lsls r1, r0, #2
+
+ #ifdef __HAVE_FEATURE_IT
+ do_it ne, t
+ #else
+ beq LLSYM(__ctz1)
+ #endif
+
+ // Out of 4 bits, the first '1' is somewhere in the lowest 2,
+ // so the higher 2 bits are no longer interesting.
+ IT(mov,ne) r0, r1
+ IT(sub,ne) r2, #2
+
+ LLSYM(__ctz1):
+ // Convert remainder {0,1,2,3} in $r0[31:30] to {0,2,1,2}.
+ lsrs r0, #31
+
+ #ifdef __HAVE_FEATURE_IT
+ do_it cs, t
+ #else
+ bcc LLSYM(__ctz_zero)
+ #endif
+
+ // If bit[30] of the remainder is set, neither of these bits count
+ // towards the result. Bit[31] must be cleared.
+ // Otherwise, bit[31] becomes the final remainder.
+ IT(sub,cs) r2, #2
+ IT(eor,cs) r0, r0
+
+ #else /* !__PURE_CODE__ */
// Look up the remainder by index.
lsrs r0, #28
adr r3, LLSYM(__ctz_remainder)
ldrb r0, [r3, r0]
+ #endif /* !__PURE_CODE__ */
#endif /* !__OPTIMIZE_SIZE__ */
LLSYM(__ctz_zero):
@@ -221,8 +254,9 @@ FUNC_ENTRY ctzsi2
subs r0, r2, r0
RET
- #if (!defined(__ARM_FEATURE_CLZ) || !__ARM_FEATURE_CLZ) && \
- (!defined(__OPTIMIZE_SIZE__) || !__OPTIMIZE_SIZE__)
+ #if !(defined(__ARM_FEATURE_CLZ) && __ARM_FEATURE_CLZ) && \
+ !(defined(__OPTIMIZE_SIZE__) && __OPTIMIZE_SIZE__) && \
+ !(defined(__PURE_CODE__) && __PURE_CODE__)
.align 2
LLSYM(__ctz_remainder):
.byte 0,4,3,4,2,4,3,4,1,4,3,4,2,4,3,4
diff --git a/libgcc/config/arm/lib1funcs.S b/libgcc/config/arm/lib1funcs.S
index 5148957144b..59b2370e160 100644
--- a/libgcc/config/arm/lib1funcs.S
+++ b/libgcc/config/arm/lib1funcs.S
@@ -454,7 +454,12 @@ SYM (\name):
Use the *_START_SECTION macros for declarations that the linker should
place in a non-defailt section (e.g. ".rodata", ".text.subsection"). */
.macro FUNC_START_SECTION name section
- .section \section,"x"
+#ifdef __PURE_CODE__
+ /* SHF_ARM_PURECODE | SHF_ALLOC | SHF_EXECINSTR */
+ .section \section,"0x20000006",%progbits
+#else
+ .section \section,"ax",%progbits
+#endif
.align 0
FUNC_ENTRY \name
.endm
diff --git a/libgcc/config/arm/popcnt.S b/libgcc/config/arm/popcnt.S
index 51b1ed745ee..d6f65403b5d 100644
--- a/libgcc/config/arm/popcnt.S
+++ b/libgcc/config/arm/popcnt.S
@@ -23,6 +23,29 @@
<http://www.gnu.org/licenses/>. */
+#if defined(L_popcountdi2) || defined(L_popcountsi2)
+
+.macro ldmask reg, temp, value
+ #if defined(__PURE_CODE__) && (__PURE_CODE__)
+ #ifdef NOT_ISA_TARGET_32BIT
+ movs \reg, \value
+ lsls \temp, \reg, #8
+ orrs \reg, \temp
+ lsls \temp, \reg, #16
+ orrs \reg, \temp
+ #else
+ // Assumption: __PURE_CODE__ only support M-profile.
+ movw \reg ((\value) * 0x101)
+ movt \reg ((\value) * 0x101)
+ #endif
+ #else
+ ldr \reg, =((\value) * 0x1010101)
+ #endif
+.endm
+
+#endif
+
+
#ifdef L_popcountdi2
// int __popcountdi2(int)
@@ -49,7 +72,7 @@ FUNC_START_SECTION popcountdi2 .text.sorted.libgcc.popcountdi2
#else /* !__OPTIMIZE_SIZE__ */
// Load the one-bit alternating mask.
- ldr r3, =0x55555555
+ ldmask r3, r2, 0x55
// Reduce the second word.
lsrs r2, r1, #1
@@ -62,7 +85,7 @@ FUNC_START_SECTION popcountdi2 .text.sorted.libgcc.popcountdi2
subs r0, r2
// Load the two-bit alternating mask.
- ldr r3, =0x33333333
+ ldmask r3, r2, 0x33
// Reduce the second word.
lsrs r2, r1, #2
@@ -140,7 +163,7 @@ FUNC_ENTRY popcountsi2
#else /* !__OPTIMIZE_SIZE__ */
// Load the one-bit alternating mask.
- ldr r3, =0x55555555
+ ldmask r3, r2, 0x55
// Reduce the word.
lsrs r1, r0, #1
@@ -148,7 +171,7 @@ FUNC_ENTRY popcountsi2
subs r0, r1
// Load the two-bit alternating mask.
- ldr r3, =0x33333333
+ ldmask r3, r2, 0x33
// Reduce the word.
lsrs r1, r0, #2
@@ -158,7 +181,7 @@ FUNC_ENTRY popcountsi2
adds r0, r1
// Load the four-bit alternating mask.
- ldr r3, =0x0F0F0F0F
+ ldmask r3, r2, 0x0F
// Reduce the word.
lsrs r1, r0, #4
--
2.25.1
