Thanks for the reply. I have already looked in there and although it gives some of the flags it is not an exhaustive list.
below is the STM32CubeIDE .s output followed by the Atollic output both have been re formated for clarity.
STM32CubeIDE
.cpu cortex-m7
.eabi_attribute 28, 1 @ Tag_ABI_VFP_args
.eabi_attribute 20, 1 @ Tag_ABI_FP_denormal
.eabi_attribute 21, 1 @ Tag_ABI_FP_exceptions
.eabi_attribute 23, 3 @ Tag_ABI_FP_number_model
.eabi_attribute 24, 1 @ Tag_ABI_align8_needed
.eabi_attribute 25, 1 @ Tag_ABI_align8_preserved
.eabi_attribute 26, 1 @ Tag_ABI_enum_size
.eabi_attribute 30, 6 @ Tag_ABI_optimization_goals
.eabi_attribute 34, 1 @ Tag_CPU_unaligned_access
.eabi_attribute 18, 4 @ Tag_ABI_PCS_wchar_t
.file "P5000_CODI_Modbus_Test_Board.c"
GNU C11 (GNU Tools for STM32 9-2020-q2-update.20201001-1621) version 9.3.1 20200408 (release) (arm-none-eabi)
compiled by GNU C version 5.3.1 20160211, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version isl-0.18-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
options passed:
-fpreprocessed Src\P5000_CODI_Modbus_Test_Board.i
-mcpu=cortex-m7
-mfpu=fpv5-d16
-mfloat-abi=hard
-mthumb
-march=armv7e-m+fp.dp
-auxbase-strip Src\P5000_CODI_Modbus_Test_Board.o
-g
-O0
-Wall
-std=gnu11
-fverbose-asm
-ffunction-sections
-fdata-sections
-fstack-usage
options enabled:
-faggressive-loop-optimizations
-fassume-phsa
-fauto-inc-dec
-fcommon
-fdata-sections
-fdelete-null-pointer-checks
-fdwarf2-cfi-asm
-fearly-inlining
-feliminate-unused-debug-types
-ffp-int-builtin-inexact
-ffunction-cse
-ffunction-sections
-fgcse-lm
-fgnu-runtime
-fgnu-unique
-fident
-finline-atomics
-fipa-stack-alignment
-fira-hoist-pressure
-fira-share-save-slots
-fira-share-spill-slots
-fivopts
-fkeep-static-consts
-fleading-underscore
-flifetime-dse
-flto-odr-type-merging
-fmath-errno
-fmerge-debug-strings
-fpeephole
-fplt
-fprefetch-loop-arrays
-freg-struct-return
-fsched-critical-path-heuristic
-fsched-dep-count-heuristic
-fsched-group-heuristic
-fsched-interblock
-fsched-last-insn-heuristic
-fsched-rank-heuristic
-fsched-spec
-fsched-spec-insn-heuristic
-fsched-stalled-insns-dep
-fsemantic-interposition
-fshow-column
-fshrink-wrap-separate
-fsigned-zeros
-fsplit-ivs-in-unroller
-fssa-backprop
-fstdarg-opt
-fstrict-volatile-bitfields
-fsync-libcalls
-ftrapping-math
-ftree-cselim
-ftree-forwprop
-ftree-loop-if-convert
-ftree-loop-im
-ftree-loop-ivcanon
-ftree-loop-optimize
-ftree-parallelize-loops= -ftree-phiprop
-ftree-reassoc
-ftree-scev-cprop
-funit-at-a-time
-fverbose-asm
-fzero-initialized-in-bss
-masm-syntax-unified
-mbe32 -mlittle-endian
-mpic-data-is-text-relative
-msched-prolog
-mthumb
-munaligned-access
-mvectorize-with-neon-quad
Atollic TrueSTUDIO
.cpu cortex-m7
.eabi_attribute 28, 1 @ Tag_ABI_VFP_args
.eabi_attribute 20, 1 @ Tag_ABI_FP_denormal
.eabi_attribute 21, 1 @ Tag_ABI_FP_exceptions
.eabi_attribute 23, 3 @ Tag_ABI_FP_number_model
.eabi_attribute 24, 1 @ Tag_ABI_align8_needed
.eabi_attribute 25, 1 @ Tag_ABI_align8_preserved
.eabi_attribute 26, 1 @ Tag_ABI_enum_size
.eabi_attribute 30, 6 @ Tag_ABI_optimization_goals
.eabi_attribute 34, 1 @ Tag_CPU_unaligned_access
.eabi_attribute 18, 4 @ Tag_ABI_PCS_wchar_t
.file "P5000_CODI_Modbus_Test_Board.c"
@ GNU C11 (GNU Tools for ARM Embedded Processors (Build 17.03)) version 6.3.1 20170215 (release) [ARM/embedded-6-branch revision 245512] (arm-atollic-eabi)
@ compiled by GNU C version 5.3.1 20160211, GMP version 6.1.0, MPFR version 3.1.4, MPC version 1.0.3, isl version 0.15
@ GGC heuristics:
--param ggc-min-expand=100
--param ggc-min-heapsize=131072
@ options passed:
-fpreprocessed Src\P5000_CODI_Modbus_Test_Board.i
@
-mthumb
-mcpu=cortex-m7
-mfloat-abi=hard
-mfpu=fpv5-d16
@
-auxbase-strip Src\P5000_CODI_Modbus_Test_Board.o
-g
-O0
-Wall
-std=gnu11
@
-fverbose-asm
-ffunction-sections
-fdata-sections
-fstack-usage
@ options enabled:
-faggressive-loop-optimizations
-fauto-inc-dec
-fchkp-check-incomplete-type
-fchkp-check-read
-fchkp-check-write
-fchkp-instrument-calls
-fchkp-narrow-bounds
-fchkp-optimize
-fchkp-store-bounds
-fchkp-use-static-bounds
-fchkp-use-static-const-bounds
-fchkp-use-wrappers
-fcommon
-fdata-sections
-fdelete-null-pointer-checks
-fdwarf2-cfi-asm
-fearly-inlining
-feliminate-unused-debug-types
-ffunction-cse
-ffunction-sections
-fgcse-lm
-fgnu-runtime
-fgnu-unique
-fident
-finline-atomics
-fira-hoist-pressure
-fira-share-save-slots
-fira-share-spill-slots
-fivopts
-fkeep-static-consts
-fleading-underscore
-flifetime-dse
-flto-odr-type-merging
-fmath-errno
-fmerge-debug-strings
-fpeephole
-fplt
-fprefetch-loop-arrays
-freg-struct-return
-fsched-critical-path-heuristic
-fsched-dep-count-heuristic
-fsched-group-heuristic
-fsched-interblock
-fsched-last-insn-heuristic
-fsched-rank-heuristic
-fsched-spec
-fsched-spec-insn-heuristic
-fsched-stalled-insns-dep
-fsemantic-interposition
-fshow-column
-fsigned-zeros
-fsplit-ivs-in-unroller
-fssa-backprop
-fstdarg-opt
-fstrict-volatile-bitfields
-fsync-libcalls
-ftrapping-math
-ftree-cselim
-ftree-forwprop
-ftree-loop-if-convert
-ftree-loop-im
-ftree-loop-ivcanon
-ftree-loop-optimize
-ftree-parallelize-loops= -ftree-phiprop
-ftree-reassoc
-ftree-scev-cprop
-funit-at-a-time
-fverbose-asm
-fzero-initialized-in-bss
-masm-syntax-unified
-mlittle-endian
-mpic-data-is-text-relative
-msched-prolog
-mthumb
-munaligned-access
-munaligned-double-access
-mvectorize-with-neon-quad
Somebody has determined these flags, but I cannot find anywhere within the ST's directories that define them, also optimizations is set to -O0 (None)
