JIT: Merge fgRemoveConditionalJump and fgOptimizeBranchToNext

[amanasifkhalid]

Adding this back in after #97407. fgRemoveConditionalJump and fgOptimizeBranchToNext do the same thing, except that the latter explicitly assumes the false target of the BBJ_COND block being optimized is the next block. It makes sense to remove that assumption, and merge these methods before allowing the false target to diverge from the next block during flowgraph optimization phases.

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Issue Details

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Adding this back in after #97407. fgRemoveConditionalJump and fgOptimizeBranchToNext do the same thing, except that the latter explicitly assumes the false target of the BBJ_COND block being optimized is the next block. It makes sense to remove that assumption, and merge these methods before allowing the false target to diverge from the next block during flowgraph optimization phases.

Author:	amanasifkhalid
Assignees:	amanasifkhalid
Labels:	area-CodeGen-coreclr
Milestone:	-

[amanasifkhalid]

cc @dotnet/jit-contrib, @AndyAyersMS PTAL. Small improvements from slightly more aggressive statement removal.

[ryujit-bot]

Diff results for #97456

Assembly diffs

Assembly diffs for linux/arm64 ran on windows/x64

Diffs are based on 2,501,157 contexts (1,003,806 MinOpts, 1,497,351 FullOpts).

MISSED contexts: 4,060 (0.16%)

Overall (-60 bytes)

Collection	Base size (bytes)	Diff size (bytes)
libraries.pmi.linux.arm64.checked.mch	76,022,852	-36
libraries_tests_no_tiered_compilation.run.linux.arm64.Release.mch	162,656,488	-24

FullOpts (-60 bytes)

Collection	Base size (bytes)	Diff size (bytes)
libraries.pmi.linux.arm64.checked.mch	75,902,868	-36
libraries_tests_no_tiered_compilation.run.linux.arm64.Release.mch	149,175,276	-24

Assembly diffs for linux/x64 ran on windows/x64

Diffs are based on 2,595,007 contexts (1,052,329 MinOpts, 1,542,678 FullOpts).

MISSED contexts: 3,628 (0.14%)

Overall (-1,818 bytes)

Collection	Base size (bytes)	Diff size (bytes)
benchmarks.run.linux.x64.checked.mch	13,735,124	-72
benchmarks.run_pgo.linux.x64.checked.mch	68,635,056	-19
benchmarks.run_tiered.linux.x64.checked.mch	17,373,152	-3
coreclr_tests.run.linux.x64.checked.mch	459,550,097	-47
libraries.crossgen2.linux.x64.checked.mch	38,670,232	-69
libraries.pmi.linux.x64.checked.mch	60,144,132	-481
libraries_tests.run.linux.x64.Release.mch	333,558,929	-711
libraries_tests_no_tiered_compilation.run.linux.x64.Release.mch	130,468,363	-344
realworld.run.linux.x64.checked.mch	13,194,603	-72

FullOpts (-1,818 bytes)

Collection	Base size (bytes)	Diff size (bytes)
benchmarks.run.linux.x64.checked.mch	13,468,331	-72
benchmarks.run_pgo.linux.x64.checked.mch	48,805,299	-19
benchmarks.run_tiered.linux.x64.checked.mch	3,695,392	-3
coreclr_tests.run.linux.x64.checked.mch	132,991,962	-47
libraries.crossgen2.linux.x64.checked.mch	38,669,030	-69
libraries.pmi.linux.x64.checked.mch	60,031,262	-481
libraries_tests.run.linux.x64.Release.mch	149,169,408	-711
libraries_tests_no_tiered_compilation.run.linux.x64.Release.mch	119,809,892	-344
realworld.run.linux.x64.checked.mch	12,805,497	-72

Assembly diffs for osx/arm64 ran on windows/x64

Diffs are based on 2,262,709 contexts (930,876 MinOpts, 1,331,833 FullOpts).

MISSED contexts: 3,256 (0.14%)

Overall (-60 bytes)

Collection	Base size (bytes)	Diff size (bytes)
libraries.pmi.osx.arm64.checked.mch	79,955,476	-36
libraries_tests_no_tiered_compilation.run.osx.arm64.Release.mch	160,911,076	-24

FullOpts (-60 bytes)

Collection	Base size (bytes)	Diff size (bytes)
libraries.pmi.osx.arm64.checked.mch	79,834,348	-36
libraries_tests_no_tiered_compilation.run.osx.arm64.Release.mch	147,773,548	-24

Assembly diffs for windows/arm64 ran on windows/x64

Diffs are based on 2,318,207 contexts (931,543 MinOpts, 1,386,664 FullOpts).

MISSED contexts: 2,687 (0.12%)

Overall (-100 bytes)

Collection	Base size (bytes)	Diff size (bytes)
coreclr_tests.run.windows.arm64.checked.mch	495,372,096	-24
libraries.pmi.windows.arm64.checked.mch	79,594,724	-36
libraries_tests.run.windows.arm64.Release.mch	310,511,308	-16
libraries_tests_no_tiered_compilation.run.windows.arm64.Release.mch	169,134,348	-24

FullOpts (-100 bytes)

Collection	Base size (bytes)	Diff size (bytes)
coreclr_tests.run.windows.arm64.checked.mch	156,280,568	-24
libraries.pmi.windows.arm64.checked.mch	79,474,740	-36
libraries_tests.run.windows.arm64.Release.mch	108,929,804	-16
libraries_tests_no_tiered_compilation.run.windows.arm64.Release.mch	155,996,884	-24

Assembly diffs for windows/x64 ran on windows/x64

Diffs are based on 2,492,912 contexts (983,689 MinOpts, 1,509,223 FullOpts).

MISSED contexts: 3,899 (0.16%)

Overall (-1,531 bytes)

Collection	Base size (bytes)	Diff size (bytes)
aspnet.run.windows.x64.checked.mch	42,178,256	-74
benchmarks.run.windows.x64.checked.mch	8,747,570	-67
coreclr_tests.run.windows.x64.checked.mch	393,404,923	-120
libraries.crossgen2.windows.x64.checked.mch	39,443,922	-70
libraries.pmi.windows.x64.checked.mch	61,389,190	-447
libraries_tests.run.windows.x64.Release.mch	281,642,309	-383
libraries_tests_no_tiered_compilation.run.windows.x64.Release.mch	133,913,806	-296
realworld.run.windows.x64.checked.mch	14,170,687	-74

FullOpts (-1,531 bytes)

Collection	Base size (bytes)	Diff size (bytes)
aspnet.run.windows.x64.checked.mch	27,519,531	-74
benchmarks.run.windows.x64.checked.mch	8,747,209	-67
coreclr_tests.run.windows.x64.checked.mch	119,861,931	-120
libraries.crossgen2.windows.x64.checked.mch	39,442,733	-70
libraries.pmi.windows.x64.checked.mch	61,275,671	-447
libraries_tests.run.windows.x64.Release.mch	103,273,993	-383
libraries_tests_no_tiered_compilation.run.windows.x64.Release.mch	123,490,436	-296
realworld.run.windows.x64.checked.mch	13,780,982	-74

Details here

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Assembly diffs for linux/arm ran on windows/x86

Diffs are based on 2,237,690 contexts (827,812 MinOpts, 1,409,878 FullOpts).

MISSED contexts: 74,588 (3.23%)

Overall (-1,314 bytes)

Collection	Base size (bytes)	Diff size (bytes)
benchmarks.run.linux.arm.checked.mch	15,303,134	-66
benchmarks.run_pgo.linux.arm.checked.mch	61,262,128	-138
benchmarks.run_tiered.linux.arm.checked.mch	22,643,448	-56
coreclr_tests.run.linux.arm.checked.mch	321,791,116	-70
libraries.crossgen2.linux.arm.checked.mch	35,175,262	-70
libraries.pmi.linux.arm.checked.mch	49,615,946	-290
libraries_tests.run.linux.arm.Release.mch	242,762,120	-400
libraries_tests_no_tiered_compilation.run.linux.arm.Release.mch	93,201,612	-174
realworld.run.linux.arm.checked.mch	13,613,446	-50

FullOpts (-1,314 bytes)

Collection	Base size (bytes)	Diff size (bytes)
benchmarks.run.linux.arm.checked.mch	14,913,878	-66
benchmarks.run_pgo.linux.arm.checked.mch	50,464,526	-138
benchmarks.run_tiered.linux.arm.checked.mch	13,536,292	-56
coreclr_tests.run.linux.arm.checked.mch	109,060,982	-70
libraries.crossgen2.linux.arm.checked.mch	35,174,032	-70
libraries.pmi.linux.arm.checked.mch	49,509,442	-290
libraries_tests.run.linux.arm.Release.mch	120,759,176	-400
libraries_tests_no_tiered_compilation.run.linux.arm.Release.mch	83,117,792	-174
realworld.run.linux.arm.checked.mch	13,163,500	-50

Assembly diffs for windows/x86 ran on windows/x86

Diffs are based on 2,296,277 contexts (841,817 MinOpts, 1,454,460 FullOpts).

MISSED contexts: 5,093 (0.22%)

Overall (-1,067 bytes)

Collection	Base size (bytes)	Diff size (bytes)
benchmarks.run.windows.x86.checked.mch	7,107,453	-50
benchmarks.run_pgo.windows.x86.checked.mch	45,222,512	-30
benchmarks.run_tiered.windows.x86.checked.mch	9,511,426	-40
coreclr_tests.run.windows.x86.checked.mch	309,180,492	-70
libraries.crossgen2.windows.x86.checked.mch	31,628,298	-84
libraries.pmi.windows.x86.checked.mch	48,827,886	-314
libraries_tests.run.windows.x86.Release.mch	185,843,933	-224
libraries_tests_no_tiered_compilation.run.windows.x86.Release.mch	102,198,175	-200
realworld.run.windows.x86.checked.mch	11,363,356	-55

FullOpts (-1,067 bytes)

Collection	Base size (bytes)	Diff size (bytes)
benchmarks.run.windows.x86.checked.mch	7,107,174	-50
benchmarks.run_pgo.windows.x86.checked.mch	38,593,022	-30
benchmarks.run_tiered.windows.x86.checked.mch	5,241,617	-40
coreclr_tests.run.windows.x86.checked.mch	107,508,723	-70
libraries.crossgen2.windows.x86.checked.mch	31,627,241	-84
libraries.pmi.windows.x86.checked.mch	48,732,572	-314
libraries_tests.run.windows.x86.Release.mch	87,512,426	-224
libraries_tests_no_tiered_compilation.run.windows.x86.Release.mch	93,528,383	-200
realworld.run.windows.x86.checked.mch	11,067,656	-55

Details here

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Throughput diffs

Throughput diffs for linux/arm ran on windows/x86

Overall (-0.01% to -0.00%)

Collection	PDIFF
benchmarks.run_pgo.linux.arm.checked.mch	-0.01%
libraries_tests.run.linux.arm.Release.mch	-0.01%

FullOpts (-0.01% to -0.00%)

Collection	PDIFF
benchmarks.run_pgo.linux.arm.checked.mch	-0.01%
libraries_tests.run.linux.arm.Release.mch	-0.01%

Details here

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[amanasifkhalid]

cc @dotnet/jit-contrib, bumping this since the diffs in #97488 are skewed without it.

[amanasifkhalid]

Thank you!